System and method for attaching soft tissue to bone

ABSTRACT

Disclosed herein are methods and devices for securing soft tissue to a rigid material such as bone. A bone anchor is described that comprises an anchor body with expandable tines and a spreader that expands the tines into bone. Also disclosed is a bone anchor that comprises a base and a top such that suture material may be attached to apertures in the anchor top or else compressed between surfaces on the base and top to secure the suture to the anchor. Also described is an inserter that can be used to insert the bone anchor into bone and move the spreader relative to the anchor body attach suture material. Also described is an inserter that can be used to insert the bone anchor into bone and move the anchor top relative to the anchor body or anchor base to attach to or clamp suture material there between. Methods are described that allow use of single bone anchor to secure tissue to bone or also to use more than one bone anchor to provide multiple lengths of suture material to compress a large area of soft tissue against bone.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Nos.61/148,805, filed on Jan. 30, 2009; and 61/251,199, filed on Oct. 13,2009; both of which are incorporated herein by reference in theirentirety.

BACKGROUND

1. Field of the Invention

The present invention relates to medical devices. Some embodimentsrelate to a bone anchor for securing body tissue to bone.

2. Description of the Related Art

There are several medical procedures where a surgeon needs to attachsoft tissue such as tendons or other soft connective tissue to bone. Onecommon example is a torn rotator cuff, where the supraspinatus tendonhas separated from the humerus causing pain and loss of ability toelevate and externally rotate the arm. To repair a torn rotator cuff,typically a surgical procedure is used to suture the torn tendon to thebone using a variety of methods. Some procedures utilize large incisionsand involve complete detachment of the deltoid muscle from the acromion.Small diameter holes are made in the bone for passing suture materialthrough the bone to secure the tendon. Such large incision proceduresare traumatic, causing prolonged pain and recovery time. Otherprocedures make small incisions and use arthroscopic techniques toattach sutures using either small diameter holes or a bendable tine.Other injuries requiring similar techniques include biceps tendonitis(e.g., a biceps tenodesis procedure) and a torn ACL.

Currently, there are various staple and anchor devices for attachingsoft tissue to bone. However, many of these devices suffer from lowpull-out strength, a lack of adequate suture attachment sites, arequirement to tie complicated knots with the sutures, complicatedthreading routines, a failure to assist the surgeon in positioning softtissue into contact with bone prior to suturing to maximize bonding ofthe soft tissue to bone, and an overall difficulty in physicallyhandling the devices during surgery.

Generally, injury to joints such as the shoulder and knee involve thetearing or separation of ligaments from their natural position on thebone. The injury leads to a chronic instability in the joint whichrequires surgical intervention. Modernly, the surgery involves use ofone or more arthroscopic devices. These devices include surgicalcannulas through which a camera or surgical device are passed. Thearthroscopic methods usually involve reduced trauma to the patient thanprevious methods and can predict a faster recovery.

In brief, the surgical procedures involve visualization and localizationof the damage, preparation of the bone surface, implantation of a softtissue anchor, and suturing of the tissue to the anchor. By tightlycontacting the ligament or other soft tissue to a properly prepared bonesurface, the two materials bond during the healing process.

However, it is difficult to manipulate sutures within the surgical siteusing arthroscopic techniques. In some techniques, such as knot tying,it is difficult to properly adjust the tension of the suture whiletightening the knot. Thus, there is a need for improved methods anddevices that allow easy arthroscopic repair of soft tissue injuries. Itis understood that the methods and devices described herein areapplicable to other surgical procedures, whether the surgery isarthroscopic or open.

SUMMARY

One embodiment disclosed herein includes an anchor for attaching tissueto bone that includes an anchor body comprising an axial bore, aplurality of bone-engaging tines extending distally from the anchorbody, a spreader comprising an axial bore, and a suture loop extendingthrough the axial bore, wherein the suture loop is secured against beingpulled through the axial bore, the spreader is configured to bepositioned between the bone-engaging tines, and the spreader isconfigured to expand the tines outward upon distal or proximal movementof the spreader relative to the anchor body.

Another embodiment disclosed herein includes a bone anchor that includesa anchor body comprising an axial bore, a plurality of bone-engagingtines extending distally from the anchor body, and a spreader positionedbetween the bone-engaging tines, wherein the spreader is configured toexpand the tines outward upon distal movement of the spreader relativeto the anchor body, wherein the spreader comprises two suture channelsconfigured in a cross pattern, wherein each channel is configured toreceive a suture loop.

Another embodiment disclosed herein includes a bone anchor inserter thatincludes a proximal handle portion, an outer tube coupled to the handleportion, an actuator coupled to the handle portion, an inner tubecoupled to the actuator and located inside of the outer tube, whereinthe actuator is configured such that movement of the actuator relativeto the handle portion causes the inner tube or rod to move axiallyrelative to the outer tube, and an aperture in the handle portionconfigured to allow the passing of sutures from the inner tube tooutside of the inserter.

Another embodiment disclosed herein includes a bone anchor and anchorinserter combination, wherein the bone anchor includes a anchor bodycomprising an axial bore, a plurality of bone-engaging tines extendingdistally from the anchor body, and a spreader positioned between thebone-engaging tines, wherein the spreader is configured to expand thetines outward upon distal or proximal movement of the spreader relativeto the anchor body, and at least one suture loop threaded within thespreader. The anchor inserter can include a handle portion, an outertube coupled to the handle portion, an actuator coupled to the handleportion and the inner tube, and an inner tube coupled to the actuatorand located inside of the outer tube, wherein the inner tube is alsocoupled to the spreader, wherein the actuator is configured to such thatmovement of the actuator causes the inner tube and hence the spreader tomove axially relative to the outer tube.

Another embodiment disclosed herein includes a method of attachingtissue to bone including inserting a bone anchor in a pre-formed bonehole using an insertion tool, advancing a spreader into the bone anchorusing the insertion tool to cause expansion of the anchor against bone,disengaging the insertion tool from the proximal end of the anchor,passing sutures which are secured to the spreader through the tissue,and fixedly securing the sutures on top of the tissue.

Another embodiment comprises a bone anchor including, an anchor bodycomprising an axial bore, a plurality of bone-engaging tines extendingdistally from the anchor body, a spreader positioned between thebone-engaging tines, wherein the spreader is configured to expand thetines outward upon distal or proximal movement of the spreader relativeto the anchor body; and one or more expandable suture capture tabscoupled to the anchor body, wherein the tabs are configured to collapseinward upon contact with sides of a pre-drilled bone hole.

Another embodiment comprises a bone anchor that is cylindrical in shape.Yet another embodiment provides an anchor body with exterior threads.Still another embodiment provides a bone anchor of claim where the axialbore has interior threads.

Another embodiment provides a bone anchor, wherein the bone-engagingtines comprise teeth adapted to resist removal of the anchor from thebone. In one embodiment, the bone-engaging tines extend from a distalend of the anchor body or where they extend from a proximal end of theanchor body.

Another embodiment comprises a bone anchor where the spreader comprisesa distal head and a proximal shaft. In one embodiment of a bone anchor,the spreader comprises exterior threads. In another embodiment for abone anchor, the axial bore comprises interior threads configured toengage the exterior threads of the spreader.

Another embodiment provides for a bone anchor, wherein the spreadercomprises a proximal hexagonal socket. In another embodiment, thespreader tapers distally.

Another embodiment provides for a bone anchor, comprising a capconfigured to engage with a proximal end of the anchor body. In yetanother embodiment, the cap is coupled to the spreader.

Another embodiment provides for a bone anchor where the spreadercomprises one or more suture apertures.

Another embodiment provides for a bone anchor, wherein the tabs extenddistally from the distal end of the anchor body. In another embodiment,the tabs extend laterally from an outside surface of the anchor body. Inone embodiment, the tabs comprise a cut away portion of the anchor body.

Another embodiment provides for a bone anchor, including, an anchor bodycomprising an axial bore, a plurality of bone-engaging tines extendingdistally from the anchor body, a spreader positioned between thebone-engaging tines, wherein the spreader is configured to expand thetines outward upon distal movement of the spreader relative to theanchor body, and an anchor cap configured to engage the spreader and besecured within the axial bore.

Another embodiment provides for a bone anchor, wherein the anchor cap isconfigured to be secured within the axial bore by snapping into thebore. Yet another embodiment provides for a bone anchor, wherein aninside surface of the axial bore comprises threads and wherein anoutside surface of the anchor cap comprises corresponding threads andthe anchor cap is configured to be secured within the axial bore byscrewing into the bore.

Another embodiment provides for a bone anchor wherein the anchor capcomprises one or more suture apertures. In another embodiment, theanchor cap suture apertures comprise pre-threaded sutures.

Another embodiment provides for a bone anchor inserter including aproximal handle portion, an outer tube coupled to the handle portion,wherein the outer tube comprises an anchor coupling member at its distalend, an inner tube or rod coupled to the handle portion and locatedinside of the outer tube, and an actuator coupled to the handle portionand the inner tube or rod, wherein manipulation of the actuator causesthe inner tube or rod to move axially relative to the outer tube.

Another embodiment provides for an inserter wherein the outer tube isreversibly coupled to the anchor by snapping or screwing. In yet anotherembodiment for an inserter, the anchor coupling member comprises threadson an interior surface of the outer tube configured to engagecorresponding threads on a bone anchor.

Another embodiment provides for an inserter wherein the actuatorcomprises a lever and cam mechanism, wherein the cam mechanism contactsa proximal end of the inner tube or rod.

Another embodiment provides for an inserter wherein the actuatorcomprises a rotatable handle coupled to the inner tube or rod andwherein an outside surface of the inner tube or rod comprises threadsengaged with corresponding threads on another component of the inserter.

Another embodiment provides for an inserter coupled to a bone anchorthat comprises, an anchor body comprising an axial bore, a plurality ofbone-engaging tines extending distally from the anchor body, and aspreader positioned between the bone-engaging tines, wherein thespreader is configured to expand the tines outward upon distal orproximal movement of the spreader relative to the anchor body, whereinthe anchor coupling member is coupled to the anchor body and the innertube or rod is coupled to the spreader. Another embodiment furthercomprises an anchor cap configured to engage the spreader and be securedwithin the axial bore. Another embodiment provides for an inserterwherein the inner tube engages with the cap which attaches by snappingor screwing to the shaft of the spreader.

Another embodiment provides for an anchor and inserter combination thebone anchor including, an anchor body comprising an axial bore, aplurality of bone-engaging tines extending distally from the anchorbody, a spreader positioned between the bone-engaging tines, wherein thespreader is configured to expand the tines outward upon distal orproximal movement of the spreader relative to the anchor body, and ananchor cap configured to be secured within the axial bore, the anchorcap comprising at least one suture aperture, the anchor inserterincluding, a handle portion, an elongated anchor engaging portionextending distally from the handle portion, the elongated anchorengaging portion comprising an anchor coupling member configured tocouple with the anchor body and a cap coupling member configured tocouple with the anchor cap, and at least one wire expanding from thehandle portion through at least one aperture in the anchor cap. Anotherembodiment provides for the combination wherein the anchor couplingmember is configured to be disengageable from the anchor body. Anotherembodiment provides for a combination wherein the anchor coupling memberis configured to be snapped off the anchor body or be twisted off theanchor body. Another embodiment provides for an anchor and insertercombination wherein the at least one wire is configured to capturesutures through the apertures in the anchor cap. Another embodimentprovides for a combination wherein the at least one wire is a nitinolwire. Another embodiment provides for an anchor and inserter combinationwherein the at least one wire forms a loop. Another embodiment providesfor an anchor and inserter combination wherein the at least one wire isslidably disposed within the elongated anchor engaging portion and atleast one aperture.

Yet another embodiment provides for a bone anchor and anchor insertercombination, the bone anchor including, an anchor body comprising anaxial bore, a plurality of bone-engaging tines extending distally fromthe anchor body, and a spreader positioned between the bone-engagingtines, wherein the spreader is configured to expand the tines outwardupon distal or proximal movement of the spreader relative to the anchorbody; the anchor inserter including, a handle portion, an outer tubecoupled to the handle portion, wherein the outer tube comprises ananchor coupling member at its distal end that is coupled to the anchorbody, an inner tube or rod coupled to the handle portion and locatedinside of the outer tube, wherein the inner tube or rod is coupled tothe spreader, and an actuator coupled to the handle portion and theinner tube or rod, wherein manipulation of the actuator causes the innertube or rod and hence the spreader to move axially relative to the outertube.

Yet another embodiment provides for an anchor and inserter combinationwherein the anchor coupling member is configured to be disengageablefrom the anchor body. In another embodiment for an anchor and insertercombination, the outer tube comprises a shoulder or stopper piece at itsdistal end so that distal force may be provided by the inserter tool tothe top of the anchor while preventing the anchor from progressing toofar into the bone. In yet another embodiment provides for an anchor andinserter combination, the handle portion comprises a rotatable portionconfigured to move the inner tube or rod proximally or distally uponrotation.

Another embodiment provides for an anchor and inserter combinationwherein the handle portion comprises a slidable portion configured tomove the inner tube or rod proximally or distally upon sliding. Inanother embodiment for an anchor and inserter combination, the handleportion comprises a lever configured to move the inner tube or rodproximally or distally upon activation.

Another embodiment provides for a method of securing a bone anchor intobone, the method including, positioning a bone anchor according to claim1 in proximity to a pre-drilled bone hole, placing one or more suturestrands behind one or more of the expandable suture capture tabs,inserting the bone anchor into the bone hole, thereby collapsing thesuture tabs and securing the suture strands; and moving the spreaderproximally or distally to cause the bone-engaging tines to expandoutward.

Another embodiment provides for a method wherein the spreader is moved,distally or proximally relative to the anchor body, by a surgeon withthe use of an insertion tool to hold the spreader in place while thesurgeon exerts distal or proximal force. Yet another embodimentsprovides for a method wherein the spreader is moved proximally ordistally with an insertion tool to cause the bone-engaging tines toexpand outward.

Another embodiment provides for a method wherein the spreader locks intoposition and remains in the anchor upon full expansion of the tines.Another embodiment provides for a method comprising removing theinsertion tool after the spreader has caused the tines to expand andbecome engaged with the bone. Yet another embodiment provides for amethod wherein the anchor is even with or below the bone's surface whenthe tines are fully expanded outward and the anchor is fixed in thebone.

Another embodiment provides for a method wherein the sutures can bereleased by partially removing the anchor from the bone hole, therebyreleasing the tabs.

Another embodiment provides for a method of securing a bone anchor intobone, the method including, inserting a bone anchor in a pre-drilledbone hole, moving the spreader distally to cause the bone-engaging tinesto expand outward, and securing the anchor cap within the axial bore.

Another embodiment provides for a method wherein the anchor capcomprising one or more suture apertures. Yes another embodiment,provides a method further comprising passing at least one length ofsuture through at least one suture aperture.

Still yet another embodiment provides for a method wherein fixedlysecuring the anchor cap to the bone anchor causes the sutures to beclamped between the anchor cap on another component of the bone anchor.

Yet another embodiment provides for a method wherein the anchor cap isadvanced to the bone anchor by an insertion tool comprising an outertube and an inner rod wherein the outer tube is coupled to the boneanchor and the inner rod is coupled to the anchor cap.

Another embodiment provides for a method wherein the sutures are alsocoupled with another bone anchor already inserted and engaged with thebone such that after fixedly securing the anchor cap to the bone anchor,suture is secured between the two bone anchors.

Another embodiment provides for a method wherein the anchor cap issecured within the axial bore by engaging with threads on the spreaderin a screwing motion or by snap-fitting onto the spreader.

Another embodiment provides for a method of attaching suture to a boneanchor, the method including, inserting a first bone anchor in apre-drilled bone hole, the first bone anchor comprising an anchor capconfigured to be fixedly secured to a proximal end of the bone anchor,the anchor cap comprising one or more suture apertures, advancing one ormore wires through one or more of the suture apertures, coupling one ormore sutures with the one or more wires, withdrawing the wires throughthe suture apertures, thereby pulling the sutures through the apertures,and fixedly securing the anchor cap to the proximal end of the firstbone anchor. In one embodiment, fixedly securing the anchor cap to thefirst bone anchor causes the sutures to be clamped between the anchorcap and another component of the first bone anchor. In anotherembodiment, the method provides advancing the anchor cap to the firstbone anchor using an insertion tool comprising an outer tube and aninner rod wherein the outer tube is coupled to the first bone anchor andthe inner rod is coupled to the anchor cap.

Another embodiment provides for a method, wherein the wires are at leastpartially contained within the outer tube of the insertion tool.

Another embodiment provides for a method wherein the sutures are alsocoupled with a second bone anchor, wherein the second bone anchor isinserted and engaged with the bone prior to insertion of the first boneanchor such that after fixedly securing the anchor cap to the first boneanchor, suture is secured between the two bone anchors.

Another embodiment provides for a method wherein the one or more wirescomprise a loop and coupling the one or more sutures with the one ormore wires comprises passing one or more sutures through the loop.

Another embodiment provides for a method of attaching suture to a boneanchor, the method including, inserting a bone anchor in a pre-drilledbone hole, passing one or more suture strands through one or more sutureapertures in an anchor top configured to couple to the proximal end ofthe bone anchor, wherein during said passing, the anchor top is notcoupled to the bone anchor, sliding the anchor top down the suturestrands until the anchor top is in proximity to the bone anchor; andfixedly securing the anchor top to the proximal end of the bone anchor.

Another embodiment provides for a method wherein passing the one or moresuture strands through the one or more suture apertures is conductedoutside of a patient's body.

Yet another embodiment provides for a method where sliding the anchortop down the suture strands comprises transporting the anchor topthrough a cannula inserted into the patient's body.

In another embodiment provides for a method wherein fixedly securing theanchor cap to the bone anchor causes the sutures to be clamped betweenthe anchor cap and another component of the bone anchor.

Another embodiment provides for a method wherein the bone anchor isfully inserted and secured to the bone before the anchor top is fixedlysecured onto the bone anchor.

Yet another embodiment provides for a method wherein the anchor capcomprises ridges in a region where the sutures are clamped between theanchor cap and another component of the bone anchor.

Another embodiment provides for a method wherein the sutures aretensioned before final insertion of the cap is fixedly secured to thebone anchor.

Still another embodiment provides a method of manufacturing a boneanchor, including, cutting a pattern into a flat piece of material andstamping the flat piece of material with successive dies to obtain thebone anchor shape. In one embodiment, the flat piece of material is oneof: titanium stainless steel, plastic, polymeric materials andfiberglass.

Another method provides where the pattern is cut into the flat piece ofmaterial by a laser or by chemical etching and then is stamped into asheet of material and bent or folded to form a three-dimensional anchor.

The present embodiment is particularly suited for use in arthroscopicprocedures, including but not limited to rotator cuff surgery, bicepstenodesis, and repair of a torn ACL. More broadly, it can be used in anyprocedure in which it is desired to fix soft tissue to bone, includingnot only arthroscopic procedures, but also open surgery, and can be usedfor such diverse purposes as bladder neck suspension, tendon andligament affixation or repair, prosthetic attachment, and rotator cuffrepair.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a side perspective view of one embodiment of a sutureanchor in an undeployed or unexpanded state.

FIG. 1B shows a perspective view of one embodiment of an undeployedsuture anchor wherein the spreader is partially inserted into the boneanchor.

FIG. 1C shows a side view of one embodiment of a suture anchor in thedeployed or expanded state.

FIG. 1D shows a perspective view of one embodiment of a suture anchor inthe deployed or expanded state.

FIG. 1E shows another perspective view of one embodiment of a sutureanchor in the deployed or expanded state.

FIG. 2A depicts a side view of one embodiment of an anchor body.

FIG. 2B depicts a perspective view of one embodiment of an anchor body.

FIG. 2C depicts another perspective proximal view of one embodiment ofan anchor body.

FIG. 2D depicts a perspective distal view of one embodiment of an anchorbody.

FIGS. 2E and 2F depict an alternate embodiment of an anchor body.

FIG. 3A depicts a side perspective view of one embodiment of a spreader.

FIG. 3B depicts a perspective view of one embodiment of a spreader

FIG. 4 shows an exploded view of one embodiment of an inserter tool.

FIG. 5A shows a perspective view of one embodiment of an inner tubecomponent of an insertion tool.

FIG. 5B shows a view of one embodiment a suture loop.

FIG. 6 shows a perspective view of one embodiment of an outer tubecomponent of an insertion tool.

FIG. 7A shows a side view of one embodiment of a handle component of aninsertion tool.

FIG. 7B shows a perspective view of one embodiment of a handle componentof an insertion tool.

FIG. 8 shows one embodiment of an actuator shaft component of aninsertion tool.

FIG. 9 shows one embodiment of a deployment knob component of aninsertion tool.

FIG. 10 shows the coupled inserter tool and suture anchor device in anunexpanded or undeployed state.

FIG. 11A shows a perspective view of an alternate embodiment of aspreader.

FIG. 11B shows another perspective view of an alternate embodiment of aspreader.

FIG. 11C shows a cross-sectional view of an alternate embodiment of aspreader.

FIG. 11D shows a perspective end view of an alternate embodiment of aspreader.

FIG. 11E shows a perspective exploded view of one embodiment of a sutureanchor having an alternate spreader in an undeployed or unexpandedstate.

FIG. 11F shows a perspective view of one embodiment of a suture anchorhaving an alternate embodiment of the spreader wherein the spreader ispartially inserted into the bone anchor.

FIG. 11G shows a side view of one embodiment of a suture anchor havingan alternate embodiment of the spreader in the deployed or expandedstate.

FIG. 11H shows a perspective view of one embodiment of a suture anchorhaving an alternate embodiment of the spreader in the deployed orexpanded state.

FIG. 11I shows an end view of one embodiment of a suture anchor havingan alternate embodiment of the spreader in the deployed or expandedstate.

FIG. 11J shows a side view of one embodiment of a suture anchor havingan alternate embodiment of the spreader coupled to an insertion tool.

FIGS. 12A-12D depict an alternative embodiment of the anchor andinsertion tool using a pull-through instead of a push-through motion.

FIGS. 13A and 13B depict an alternative embodiment of the anchor andspreader in which the tines expand from the proximal end of the anchor.

FIG. 14 depicts the anchor with tabs and tines.

FIG. 15 depicts an alternative embodiment of the anchor.

FIG. 16 depicts an anchor with bent tabs and tines.

FIG. 17 depicts various embodiments of the spreader device and optionalcaps.

FIGS. 18A and 18B depict an embodiment of a piercing bendable tine in anun-deployed (FIG. 18A) and deployed (FIG. 18B) state. FIGS. 18A and 18Bdepict an embodiment of the anchor with an insertion tool that uses ahex and screw configuration.

FIG. 19 depicts an embodiment of an insertion tool.

FIG. 20A depicts another embodiment of an insertion tool.

FIG. 20B depicts a cut-away view of an embodiment of an insertion tool.

FIG. 21 depicts an insertion tool utilizing a cam and lever.

FIG. 22 depicts a stopper component on an embodiment of an insertiontool.

FIG. 23 depicts an embodiment of an anchor and cap using nitinol loopsto thread the sutures.

FIGS. 24A and 24B depict an alternative embodiment of the anchor using aslideable cap threaded with sutures to secure the sutures between thecap and the anchor.

FIG. 25 depicts an embodiment of a bendable tine stamped from a singlesheet of metal during the bendable tine manufacturing process.

FIG. 26A shows a single-row rotator cuff repair using two sutureanchors.

FIG. 26B shows a double-row rotator cuff repair using four sutureanchors.

FIGS. 27A-27E depict manipulation of an embodiment of a suture anchorusing a suture anchor inserter to insert the suture anchor into bone andattach suture material to the suture anchor.

FIGS. 28A-28D depict various geometries produced by the use of multipleanchors, anchors, and sutures.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

Various embodiments include an anchor that can be inserted into bone andto which sutures can be attached. In one embodiment, the anchorcomprises expandable tines that secure the anchor in bone afterinsertion. In some embodiments, a spreader is provided that can be usedto expand the tines. Some embodiments include one or more suture lengthsthat are pre-attached to the spreader.

In various embodiments, soft tissue may be attached to bone utilizingone or more suture anchors. FIG. 1A depicts a side perspective view of asuture anchor 100 comprising an anchor body 200 and a spreader 300. Theanchor body 200 is comprised of tines 220 and teeth 230. The tines 220expand from the distal end of the anchor body 200 when the spreader 300is engaged with the anchor body 200. The proximal end of the spreader300 is configured to fit into the distal end of the anchor body 200. InFIG. 1A, the suture anchor 100 is in the undeployed, or unexpandedposition. A suture loop 550 extends through the anchor body 200 and thespreader 300 where it is securely knotted 350 outside of the distal endof the spreader 300. The knotted suture 350 is tightened, such thatsuture loop 550 forms a tightened knot that cannot pass back through thespreader 300 or the anchor body 200 but rather is fixed outside of thespreader 300. Alternatively, the suture loop may be secured againstbeing pulled through the spreader 300 using securement mechanisms otherthan knot, such as cross-pin or biocompatible adhesive.

FIG. 1B shows another side perspective view of the unexpanded sutureanchor 100. In this embodiment, the spreader 300 is slightly inserted inthe axial bore 215 at the distal end of the anchor body 200.

FIG. 1C shows a side view of the suture anchor 100 in the deployed orexpanded position. In the deployed or expanded position, the spreader300 has been drawn up into the anchor body 200 causing the tines 220 toexpand from the distal end of the anchor body 200. When deployed, theteeth 230 engage with the bone, thereby securing the anchor within thebone.

The inside surface of the anchor body 200 may comprise a grooved surface225 to engage with the ridge 315 of the spreader 300 to lock thespreader 300 into place when the anchor body 200 is fully deployed. Inone embodiment, the grooved surface 225 is on the inside surface of oneor more of the times 220. The grooved surface 225 is oriented such thatthe distal end of the spreader 300 can be easily moved in the proximaldirection in axial bore 215 of the anchor body 200 with the ridge 315snapping into the groove 225 as the distal end is moved proximally.However, when the ridge 315 is snapped into groove 225, distal movementof distal end is inhibited. In some embodiments, the groove 225 canexist at different locations on the inside surface of the axial bore oreven along substantially the entire inside surface of the axial bore215. In some embodiments the anchor body 200 may be coupled to thespreader 300 in several positions, such as by inclusion of multiplegrooves. In other words, in one embodiment the spreader 300 need not beinserted into the anchor body 200 as far as it will go for it to besecured to the anchor body 200.

Although a grooved surface is illustrated, it will be appreciated thatother shapes are also contemplated, including multiple concentricgrooves, a series of protruding ridges, or any other suitable structurethat permits a spreader 300 to be securely locked within the anchor body200.

With reference to FIG. 1D, which is a perspective view of the top andside of anchor body 200 engaged with the spreader 300, the top (proximalend) comprises a hole 215 in the center for receiving the suture. Insome embodiments, the top surface 218 of the anchor body 200 may betextured such as with a scallop shape or grooves so as to inhibitmovement of an insertion tool against this surface.

During deployment, the spreader 300 is drawn into the anchor body 200causing the tines 220 to expand from the distal end of the anchor body200. Also during deployment, the spreader 300 is drawn into the anchorbody 200 until the ridge 315 of the spreader 300 passes a groove 225(not shown) in the anchor body 200. When the spreader passes this point,the ridge 330 and groove 225 engage or click and the spreader 300 islocked into place and the anchor body 200 cannot undeploy or reverse andthe spreader 300 cannot reverse direction.

FIG. 1E shows a distal view of the suture anchor 100. In this view theanchor body 200 is fully deployed. The spreader 300 is securely fixedinto the anchor body 200 and the ridge 315 and groove 225 of the anchorbody 200 will keep the spreader 300 from being uninserted or reversedfrom the anchor body 200. The spreader 300 will remain permanentlylocated in the bone anchor 200 to help prevent collapse, movement orslipping of the components and of the anchor 200 as a whole.

FIGS. 2A-2D depict an embodiment of an undeployed anchor body 200. FIG.2A depicts a side view of the anchor body 200. FIG. 2B depicts aperspective view of an embodiment of the anchor body 200. FIG. 2Cdepicts a view from the proximal end of the anchor body 200, and FIG. 2Ddepicts a perspective view from the distal end of the anchor body 200.

The anchor body 200 can generally have any shape, for example a circularshape, or a polygon of three or more sides. The proximal end 210 of theundeployed anchor body 200 is generally cylindrical in shape with adiameter larger than distal end 202. With reference to FIGS. 2B-2D, ahole 215 may advantageously be provided in the center of proximal end210. With reference to FIG. 2B, the bottom of distal end 202 alsocontains a hole 215. Hole 215 comprises a central bore that extendsthrough the anchor body 200. In one embodiment the anchor body 200comprises a groove 225 in its inner surface, as shown in FIGS. 2C-2D.Thus, the inner surface of the anchor body 200 is not flat. In oneembodiment, some or all of these surfaces may be textured such as with ascallop shape or grooves so as to inhibit movement of spreader 300 onceit is withdrawn into the anchor body. In one embodiment, texturing inthe inner surfaces of anchor body 200 matches texturing in the outersurfaces of the spreader 300. It will be appreciated that theillustrated embodiments represent only one possibility; thus, othershapes for the distal surface of proximal end 204 may also be used.

In the depicted embodiment, the anchor body 200 has a circular shape.The distal end 202 of the anchor body 200 is configured to receive thespreader 300 and sutures via an axial bore 215. The axial bore 215 inanchor body 200 is an opening into an axial bore into and through theanchor body 200. The sides of the bore preferably include a groove 225for engaging with the spreader 300, described below. It will beappreciated that other methods of securing the spreader 300 within theanchor body 200 may be used, such as a frictional fit or threading. Theaxial bore 104 can generally be any shape, for example, a circle shapeor a polygon shape. Circular forms are preferred for the axial bore 215.

The anchor body 200 is comprised of tines 220 which spread outwardlywhen engaged with the spreader 200. The tines 220 engage with the bonefixedly securing the anchor body 200 in the bone. The tines may comprisea plurality of teeth 230 which further engage with the bone in thedeployed suture anchor 100. When the tines 220 are expanded (spreadoutward), the teeth 230 can engage the bone to hold the anchor in place.In one embodiment, the anchors described herein provide for increasedsuture pull-out strength and to retain the tissue by multiple sutures.

In one embodiment, the anchor body 200 has from about two to about sixtines 220 extending therefrom. In a preferred embodiment, the anchorbody 200 has four tines 220 extending therefrom. Each tine 220 maycomprise, along its outward-facing edge, one or more teeth 230,preferably three to six in number, which can be engaged with the boneonce the tines 220 are spread apart after insertion of the anchor 100.Each tine's distal end can be formed to a slant or pointed edge. Inother embodiments, the distal end of each tine is either straight or anyother effective shape.

The anchor is expandable at its distal end by the tines spreadingoutward. As the tines are spread apart with the spreader (describedbelow), the teeth 230 of the tines 220 become engaged in bone materialsuch that the anchor is securely attached to the bone. Distal expansionprovides improved pull-out strength. Where multiple teeth 230 arepresent, they may increase in size as they are positioned more distallyfrom the anchor body 200. The teeth 230 are preferably tapered tosharpened points that are able to penetrate tissue and/or the interiormatrix (cancellous portion) of the bone. Once expanded, the spreader 300remains in the anchor 200.

The tines 220 are preferably symmetrically positioned about the anchorbody 200. In one embodiment, when the tines 220 are in their un-expandedconfiguration, the distal ends of the tines 220 are in a first internallateral position, as depicted in FIG. 1A and FIG. 1B, such that they areparallel to or angled internal to the longitudinal axis. In oneembodiment, the internal angle is from about 8° to about 15°. When inthe internal lateral position, the teeth 230 may be at or within thecylindrical, axially extending region defined by the anchor body 200.During and after insertion of a spreader, as the distal ends of thetines 220 are moved to their second or external, more lateral position,the distance between the ends and the longitudinal axis of the anchor100 will increase to place the tines 220 at or beyond the cylindricalaxially extending region defined by the anchor body 200. (See FIGS. 1Cand 1D).

The number of tines 220 and teeth 230 can vary. In one embodiment, thereare four tines 200 with five teeth 230 per tine 220. The distal end 210of the anchor body 200 is configured to receive a portion of an anchorinserter, which can be inserted through the hole 215 in the center ofthe anchor body 200 to couple with a spreader 300.

The distal end 202 of the anchor body 200 may advantageously be taperedto facilitate insertion of the anchor body 200 into bone. In oneembodiment, the anchor body 200 has at its widest point, a diameter notlarger than the widest point of the spreader 200.

FIGS. 2E and 2F depict an alternate embodiment of an anchor body 200. Inthis embodiment, the anchor body also comprises webbed portions 250across the distal ends of the tines 230. These webs 250 are easilybroken when the spreader 300 is engaged with the anchor body 200. Thewebs 250 protect against premature deployment of the anchor uponinsertion into the bone by keeping the tines 220 intact until they areexpanded via the spreader 300.

The exact size and dimensions of the anchor can vary with its intendeduse and the patient size. The following overall dimensions are suitedfor the shoulder and knee joints of an adult human of average size, andcan be modified for specific patients or uses. The diameter of theanchor can have, but is not limited to, a range from 3 to 10 mm.

The anchor can be made of any biocompatible or physiologically inertmaterials. In one embodiment, plastics, including but not limited topolyetheretherketone (PEEK) or other suitable materials, may be used.Other embodiments can include titanium and its alloys, stainless steel,and cobalt based alloys. Bioabsorbable materials can also be used.

FIG. 3A shows a side view of an embodiment of the spreader 300. FIG. 3Bshows a perspective view of the spreader 300. The spreader 300 comprisesa generally tube shaped base 310 at the proximal end 307 with a axialbore 325 for receiving sutures and an insertion tool, a generallyconical shaped spreader at the distal end which is wider than theproximal end, and an optional ridge 315 at the tip of the distal end.The distal end can further comprises a flat area around the axial bore325. The proximal end 307 is configured for receiving sutures andcoupling with an inserter. For instance, in this embodiment, theproximal end 307 of the spreader 300 comprises a hole 325 that receivesthe inserter tool for coupling.

The spreader 300 comprises the base section which joins with thegradually expanding distal spreader end. The distal end is generallycylindrical-shaped or cone-shaped 310, meaning that it gradually widensin a conical shape from the base section to the distal end of thespreader 300 which comprises a flat area and through which the axialbore 325 extends. In one embodiment, the distal end may also comprise aridge 315, which may optionally be slightly undercut 322 to result in astronger lock in the bone then when the anchor is fully deployed.

The axial bore 325 may be used to receive sutures (see FIGS. 1A-1E). Inone embodiment, a loop of suture is secured through the axial bore 325such that two lengths of suture extend from the spreader for use in asurgical procedure. The distal end of the spreader 300 comprises oneopening to the axial bore 325 through which the suture loop 550 extends.The resulting two suture lengths extend from the proximal end of thespreader through the axial bore 325. The suture loop 550 extendingthrough the distal end of the spreader 300 can be secured, for example,by a knot 350 in the loop such that it cannot be moved or forced backthrough the axial bore 325.

The spreader 300 is configured to be drawn through the distal end of theanchor body 200 via an insertion tool. As the suture anchor 100 isdeployed, the spreader 300 is further advanced into the anchor body 200,spreading the tines 220 of the anchor body 200 until the ridge 315 ofthe spreader 300 engages the groove 225 in the inside of the anchor body200 at which point it locks into place. In one embodiment, the ridge 315is undercut 322 providing even more security against reversing. In oneembodiment, the ridge and groove is optional.

As discussed above, the tines 220 in the anchor may be in a low-profilestreamlined position prior to insertion into bone. A spreader 300 isused after insertion to expand the tines 220 such that their teeth 225engage bone. The spreader 300 may comprise any suitable shape configuredto be inserted through the axial bore 215 in the anchor body 200 andmake contact with the tines 225. The spreader 300 may be at leastpartially positioned within the axial bore of the anchor prior to tineexpansion as depicted in FIG. 1B. As the spreader 300 is moved from afirst lower position to a second upper position, the proximal end of thespreader 300 is designed to spread or force the tines 220 from a firstlow-profile position (for example, an internal lateral position) to asecond external lateral position. In one embodiment, the proximal end ofthe spreader 300 may have ridges to assist in preventing slippage ormis-alignment.

The spreader 300 will remain in the anchor with the tines 220 in theirfully spread position. The force provided by the tines' 220 interactionwith the bone keeps the spreader 300 tightly engaged. Further protectionagainst slipping or tilting of the spreader 300 is provided by theoptionally ridged sides of the spreader 300. In one embodiment, thespreader 300 may have ridges or indentations to assist in a tight fitsuch that accidental slipping or adjustments are minimized. In oneembodiment, one or more of the tines 220 have an indentation on a sidefacing the central axis of the anchor. A ridge on the spreader can thenengage the indentation, thereby stabilizing the spreader 300 andpreventing the spreader 300 from being advanced too far into the anchor.In an alternative embodiment, the spreader comprises an indentation (forexample, an indentation in a ridge on the spreader 300) that can engagewith a protrusion on a side of a tine facing the central axis of theanchor. In addition, to stabilizing the spreader 300 and preventing overinsertion, this feature also prevents rotation of the spreader 300relative to the anchor.

In a preferred embodiment, the anchor 100 is made entirely of abiocompatible engineering plastic such as polyether-ether-ketone (PEEK).Other embodiments include an anchor entirely or in part of anon-metallic substance that is biocompatible. Biocompatible materialssuch as poly ether ketone (PEK), polyethermide (ULTEM), ultrahighmolecular weight polyethylene (UHMPE), or some other engineering polymermaterials known to those of skill in the art may be used. A non-metallicanchor system may provide certain advantages such as, for example,eliminating MRI artifacts.

FIG. 4 depicts individual components of an inserter tool. The insertertool comprises an inner tube 500, an outer tube 600, a handle body 700,a threaded actuator shaft 800, and a deployment knob 900. In oneembodiment, the inserter 400 is coupled to the suture anchor 100 duringmanufacturing. In a preferred embodiment, the inserter tool isdisposable.

The inserter tool 400 is designed to insert and manipulate a sutureanchor such as the suture anchor described in FIG. 1A and FIG. 1B. Inone embodiment, the suture anchor is manufactured to be attached to theinserter tool before packaging. In other embodiments, the suture anchoris coupled to the inserter tool prior to insertion. In a basicconfiguration, the inserter tool is assembled as follows: the insertertool 400 is configured such that the inner tube 500 is disposed withinthe outer tube 600. The outer tube is configured to fit against theproximal end of the anchor. The inner tube 500 extends through outertube 600 and is configured to attach to the spreader 300 via threadingon both the proximal hole in the spreader 300 and threading on thedistal end of the inner tube 500. The proximal end of the outer tube 600is connected to a handle 700 and the inner tube 500 extends through theproximal end of the outer tube 600 and screws into the threaded actuatorshaft 800. The actuator shaft extends just past the proximal end of thehandle 800 where it is configured to engage with a deployment knob 900.

The individual components of the inserter tool 400 are further describedin detail below.

FIG. 5A shows a perspective view of an embodiment of the inner tube 500.The inner tube comprises a distal end configured to secure to thespreader 300 and receive sutures running through the inner tube, and aproximal end which is configured to interact with the other componentsof the inserter, for example, the actuator shaft 800. The inner tube 500is configured such that its proximal end is advanced through the outertube 600 and into the handle 700 where it is further secured within theactuator shaft 800 via threading. The distal end of the inner tube 500is configured to be advanced through the axial bore in the anchor body200 and then secured to the spreader 300 until the suture anchor 100 isfully deployed and the inner tube 500 is separated from the anchor 200.

The inner tube 500 extends through the axial bore 225 in the anchor body200 before coupling with the spreader 300. In one embodiment, the innertube 500 couples with the spreader 300 through threads on the end of theinner tube 500 and within the proximal end of the spreader 300. In otherembodiments, the inner tube 500 may couple to the spreader 300 throughother securing mechanisms such as adhesions, welding or frictional fit.In some embodiments, the inner tube 500 may be an inner rod.

FIG. 5B shows an embodiment of the suture loop 550. In one embodiment,there is one suture loop. In other embodiments, there can be two or moresuture loops. In the embodiment spreader shown in FIGS. 1A-1E, there isone suture loop 550. The suture loop 550 is knotted 350 at the endextending through the axial bore of the spreader 300 and therefore thesuture 550 is not slidable through the inner tube 500. In otherembodiments, the suture loop may be slidable.

FIG. 6 shows an embodiment of the outer tube 600. The outer tube 600 isattached at its proximal end 605 to the distal end of handle 700 viathreading 625. The distal end 610 of the outer tube 600 is configuredsuch that the inner tube 500 is drawn into the outer tube 600 andthrough the distal end 610 of outer tube 600 where it is secured to thespreader 300. When the inner tube 500 is advanced far enough that thespreader 300 locks into place or cannot advance anymore, the outer tube600 is surface 225 to surface 620 with the anchor body 200 so that whenthe anchor body 200 reaches the distal end of the outer tube 600, theinner tube 500 cannot advance any further and the continued rotation ofthe deployment knob and advancement of the actuator shaft and inner tube500 strips the threading from the spreader 300 and the inner tube breaksoff.

FIGS. 7A and 7B show embodiments of a handle body 700. FIG. 7A is acut-away view of the handle body 700. The proximal end of the handle 700is configured to receive the deployment knob 900 via the ridges 730which hold the knob 900 secure. The actuator shaft 800 is housed withinthe handle body 700. A set of flat brackets or braces 710 secure theactuator shaft 800 within the handle 700. The distal end 770 of thehandle is configured to receive the outer tube 600 via threads 625. Theouter tube 600 is permanently affixed to the handle 700.

FIG. 7B depicts a cross-sectional view of one embodiment of a handle700. In FIG. 7B the flat surface 715 of the bracket 710 is shown.

Handle 700 also comprises an aperture for passing sutures through thehandle 700 and a cleat 750 for containing the sutures 550. The cleat 750secures the suture that runs from the anchor from unraveling, moving oradvancing through the inner tube 500.

FIG. 8 depicts the threaded actuator shaft 800. The actuator shaft 800is comprised of a distal end 805 comprising a threaded hole 810 which isconfigured to receive the inner tube 500, a second threaded portion 825on the body of the shaft configured to advance the inner tube 500, and aproximal end 820 configured to secure within the deployment knob 900.The threading 825 of the actuator 800 has two flat areas 830, one oneach side, where there is no threading. These flat areas 830 fit withinthe flat brackets 710 of the handle such that the actuator 800 cannotrotate within the handle, but can only advance through the handle whilealso advancing the inner tube 500.

The body of the actuator shaft 800 is configured with threading 825 topermit the shaft 800 to advance the inner tube 500. The body of theactuator shaft 800 is not perfectly round, but rather is oval shapedwith flat sides 830 that are fit into the handle body in such a way thatthe actuator shaft 800 cannot itself rotate when the deployment knob 900is turned and the shaft 800 advances via the knob 900. Thus, the threadsdo not go all the way around the shaft but rather flatten out on theflattened sides of the shaft. The actuator shaft is configured as acoaxial system. That is, the spreader 300, inner tube 500 and actuator800 are configured to operate as one piece. The flat brackets 710 in thehandle make the actuator shaft 800 stay on plane such that the actuatorshaft 800 itself cannot rotate within the handle 700. The proximal endof the inner tube 500 couples with the distal end of the actuator shaft800 via threading.

The sutures 550 are threaded through the inner tube 500 and exit theinner tube at its proximal end. When the sutures 550 exit the inner tube500 they are within the actuator shaft 800 and exit the actuator shaft800 at an aperture 850 and are threaded through a second aperture 770 inthe handle body 700 and then are wound around a cleat 750 on the outsidesurface of the handle body 700.

Moving to FIG. 9, a deployment knob 900 is shown. The deployment knob900 comprises an axial bore 910 which is configured with threading 905,and a groove 930 configured to be received by a corresponding ridge 730of the handle 700. The threading 905 in the axial bore 910 is configuredto receive the actuator shaft 800. The deployment knob 900 is configuredto advance, relative to the deployment knob 900, the inner tube 500 viathe actuator shaft 800. The actuator shaft 800 is joined at its proximalend to the distal end of the deployment knob 900 via threading 905 inthe axial bore 910. The actuator shaft 800 is attached to the inner tube500 by way of the proximal end of the inner tube 500 advancing into thedistal end of the actuator shaft via threading so that when thedeployment knob 900 is rotated, the mechanism of the shaft 800 advancesthe inner tube 500 proximally such that the spreader 300 is thenadvanced into the anchor body 200 to expand the anchor body 200 intobone and secure it in place. As the deployment handle is turned, theactuator shaft 800 is advanced in a proximal direction until the anchorbody 200 is deployed and locked into place.

FIG. 10 shows a suture anchor 100 coupled to the inserter tool 400. Thesuture anchor 100 comprises the anchor body 200 and the spreader 300.The inserter tool 400, as shown, depicts the outer tube 600, the handle800 and the deployment knob 900. The inner tube 500 (not shown) ispositioned within the outer tube 600, and the outer tube is flush withthe anchor body 200. The outer tube 600 may hold the anchor body 200steady during insertion and deployment. The inner tube 500 extendsthrough the anchor body 200 and couples with the spreader 300 viathreading. The spreader 300 is configured to be pulled through thedistal end of the anchor body 200 by the inner tube 500 via rotation ofthe deployment knob 900. The suture loop 550 is knotted 350 at the endof the spreader 300.

The inner tube 500 provides the mechanism to draw the spreader 300 intothe axial bore 225 in the anchor body 200 to fully expand the anchorbody 200. During deployment of the tissue capture anchor 100, the innertube 500 is continually advanced via a screwing motion of the knob 900until the spreader locks with the anchor body. As the deployment knob900 continues to turn and the inner tube 500 continues to pull on thethreads of the spreader 300, the inner tube 500 strips the threads fromthe inside of the spreader 300 and the insertion tool 400 snaps off atjust below the base of the anchor body 200. Any thread shavings arecontained within the outer tube 600. Alternatively, the inner tube 500may be disengaged from the spreader by un-screwing the inserter from theanchor (for example, by rotating the entire inserter relative to theanchor).

Additional Embodiments of the Spreader

FIGS. 11A-11J depict an alternate embodiment of the spreader 1100. FIG.11A shows front or distal perspective view of an embodiment of thespreader 1100. FIG. 11B shows a back, or proximal perspective view ofthe spreader 1100. FIG. 11C shows a cross-sectional view of the spreader1100. FIG. 11D shows a proximal perspective view of the spreader 1100.FIG. 11E shows a perspective view of the spreader 1100 with the anchorbody 200, and sutures 550 and 555. FIG. 11F shows a perspective view ofthe spreader 1100 engaged with the anchor body 200 but not fullydeployed. FIG. 11G shows a side view of the spreader 1100 engaged withthe bone anchor 200 in the fully deployed position. FIG. 11H shows aproximal perspective view of the spreader 1100 and bone anchor 200 fullyexpanded. FIG. 11I depicts a front full view of the spreader. FIG. 11Jshows this alternate embodiment of the spreader 1100 engaged with theinsertion tool 400.

The spreader 1100 comprises a generally tube-shaped base section 1110 atthe proximal end 1107 which joins with the gradually expanding upper end1108 of the spreader 1100. The proximal end 1107 further comprises anaxial bore 1125 for receiving sutures 550 and 555 and for receiving aninsertion tool 400, a generally conical shaped spreader at the distalend 1102 which is wider than at the proximal end, and an optional ridge1115 at the tip of the distal end for securing the spreader 1100 withinthe bone anchor 200. The generally cylindrical-shaped or cone-shapedupper end 1108 gradually widens in a conical shape from the proximal endof the base section 1110 to the distal end of the upper end 1108 of thespreader 1100. The distal end of the spreader 1100 comprises a roundedtip area 1105 through which suture channels 1127 and 1129 extend.

The distal end 1102 comprises a rounded area 1105 around channels 1127and 1129 which are configured to receive sliding sutures 550 and 555.The channels 1127 and 1129 open into axial bore 1125. The channels 1127and 1129 are configured such that the sutures 550 and 555 are arrangedin a cross shape and are freely slidable through the spreader and theinner tube and in the hands of the surgeon. As can be seen in FIG. 11C,the channels 1127 and 1129 of the axial bore 1125 allow for two distinctsuture loops to be threaded through the spreader 1100. The arrangementprovides for four suture limbs extending through the axial bore 1125 andavailable for use by the surgeon. The sutures are slidable relative tothe spreader such that when the surgeon pulls on one suture limb, thecorresponding limb on the other side of the loop will be shortened. Inone embodiment, the distal end may also comprise a ridge 1115, which maybe slightly undercut 1122 resulting in a stronger hold in the bone whenthen the anchor is fully deployed.

As further shown in FIGS. 11C, 11D, 11E and 11F, the spreader 1100comprises channels 1129 and 1127 for receiving the sutures 550 and 555.The channels 1127 and 1129 are arranged in a cross shaped pattern, thatis with one channel being perpendicular to the other and one channelbeing deeper (i.e., more proximal) than the other channel. Thisarrangement prevents one suture 550 from touching the other suture 555allowing the two sutures to slide independently without interference.FIG. 11D shows the spreader 1100 from the proximal end 1107 andillustrates how the axial bore 1125 feeds the two channels 1127 and1129. FIG. 11E shows the spreader 1100 loaded with sutures 550 and 555and additionally illustrates the two suture loops extending from thechannels 1127 and 1129.

The proximal end 1107 is configured for receiving sutures 550 and 555and coupling the spreader 1100 with an inserter. For instance, in thisembodiment, the proximal end 1107 of the spreader 1100 comprises a hole1125 that receives the inserter tool for coupling with the anchor body200.

As described above and depicted in FIG. 11F, the distal end of thespreader 1100 comprises channels 1127 a,b and 1129 a,b opening to theaxial bore 1125 through which the sutures 550 and 555 extend. Thesutures 550, 555 each are threaded through the proximal end of thespreader 1100, through the axial bore 1125 and then each into one of thechannels 1127 a and 1129 a. The sutures 550 and 555 extend out of eachchannel at the distal end of the spreader 1100 and are looped backthrough the spreader 1100 into its corresponding channel 1127 b and 1129b and through the proximal end of the spreader 1100. The sutures 550 and555 are configured to freely slide.

The spreader 1100 is configured to be drawn through the distal end ofthe anchor body 200 via an insertion tool 400. FIG. 11F illustrates theanchor body 200 partially engaged with the spreader 1100. As the sutureanchor 100 is deployed, the spreader 1100 is further advanced into theanchor body 200, spreading the tines 220 of the anchor body 200 untilthe ridge 1115 of the spreader 1100 engages the groove 225 in the insideof the anchor body 200 at which point it locks into place. In oneembodiment, the ridge 1115 is undercut 1122 providing even more securityagainst reversing. Other locking mechanisms may be employed. A fullydeployed spreader 1100 and anchor body 200 is depicted in FIG. 11G andFIG. 11H while FIG. 11I illustrates a face view of the fully deployedspreader 100 and anchor body 200.

As discussed above, the tines in the anchor may be in a low-profilestreamlined position prior to insertion into bone. A spreader 1100 maybe used after insertion to expand the tines such that their teeth 225engage bone. The spreader 1100 may comprise any suitable shapeconfigured to be inserted through the axial bore 215 in the anchor body200 and make contact with the tines 225. The spreader 1100 may be atleast partially positioned within the axial bore of the anchor prior totine expansion as depicted in FIG. 11F. As the spreader 1100 is movedfrom a first lower position to a second upper position, the proximal endof the spreader 1100 is designed to spread or force the tines 220 from afirst low-profile position (for example, an internal lateral position)to a second external lateral position. In one embodiment, the proximalend of the spreader 1100 may have ridges to assist in preventingslippage or mis-alignment.

The spreader 1100 will remain in the anchor with the tines in theirfully spread position. The force provided by the tines' interaction withthe bone keeps the spreader 1100 tightly engaged. Further protectionagainst slipping or tilting of the spreader 1100 is provided by theoptionally ridged sides of the spreader 1100. In one embodiment, thespreader 1100 may have ridges or indentations to assist in a tight fitsuch that accidental slipping or adjustments are minimized whiledeliberate withdrawals are possible after insertion into bone withoutinadvertent pull-outs. In one embodiment, one or more of the tines 220have an indentation on a side facing the central axis of the anchor. Aridge on the spreader can then engage the indentation, therebystabilizing the spreader 1100 and preventing the spreader 1100 frombeing advanced too far into the anchor. In an alternative embodiment,the spreader comprises an indentation (for example, an indentation in aridge on the spreader 1100) that can engage with a protrusion on a sideof a tine facing the central axis of the anchor. In addition, tostabilizing the spreader 1100 and preventing over insertion, thisfeature also prevents rotation of the spreader 1100 relative to theanchor.

FIG. 11J shows the alternative spreader 1100 and bone anchor 200 coupledwith the loaded, assembled insertion tool 400. The sutures 550 and 555(not shown in FIG. 11J) extend from the proximal end of the spreader1100 and through the inner tube 500 (not shown) which is situated insideof the outer tube 600. In one embodiment, the insertion tool is the sameas described above. That is, the sutures exit the inner tube 500 at itsproximal end, which is engaged with the distal end of the actuator shaft800 (not shown).

The sutures exit the actuator shaft 800 at openings in the side of theshaft 800 where they exit the handle 700 at an aperture 770. The handle700 comprises a cleat 750 for maintaining the lengths of suture loop.

Alternative Bone Anchor Embodiments 1. Alternative Locking Mechanism

In one alternative embodiment depicted in FIGS. 12A-12D, the anchor bodyand spreader are similar to those described above, except that thespreader comprises the locking groove and the anchor body comprisesprotrusions to interface with the groove. FIG. 12A is an exploded viewdepicting the inserter tool and anchor with the spreader outside of theanchor body. As above, the anchor body 1201 is configured such that thespreader 1205 is inserted into the anchor body 1201 through the spacebetween the tines in the distal portion of the anchor body 1201. In someembodiments, the spreader piece 1205 has pre-attached sutures 1203. Thesuture passes through the interior of the anchor inserter tool 1200. Insome embodiments, the suture 1203 passes through the inserter tool 1200and then out the top of the inserter for manual manipulation by asurgeon. In other embodiments, the suture 1203 is engaged with a pullingmechanism in the handle portion of the inserter. For example, the suture1203 may be coupled to a reel or lever system that can pull up on thesuture. Sutures may be fixed to the spreader 1205 or free running.

The inserter tool 1200 depicted in FIG. 12A is made of a rigid materialand can be hollow. The inserter tool 1200 can comprise at least twoconcentric tubes. The inner tube 1207 is reversible coupled to thespreader 1205 such as by external threads engaging with correspondinginternal threads in the spreader 1205. An outer tube 1210 can be used tointerface with the anchor body 1201 and provide a distal anchorinsertion force as well is keeping the anchor within the bone when aproximal pulling force is applied to the spreader 1205 by the inner tube1207. The outer tube 1210 may comprise a shoulder or stopper piece (forexample, FIG. 22 element 2205) at its distal end so that distal forcemay be provided by the inserter tool 1210 to the top of the anchor 1201and to prevent the anchor 1201 from progressing too far upwards alongthe inserter tool 1200. During insertion of the anchor 1201, thespreader is positioned between distal ends of the tines 1206 as in FIG.12B, with the spreader 1205 distal enough that the tines 1206 are notexpanded. After insertion of the two components, the inner tube ispulled by the surgeon to force the spreader 1205 proximally and therebyexpand the tines 1206. The inner tube is either unscrewed ordeliberately broken away (such as by stripping of threads between theinner tube 1207 and the spreader 1205) to remove the inserter tool fromthe anchor. Where the inner tube 1207 is unscrewed from the spreader1205, protrusions and corresponding indentations may be provided betweenthe spreader 1205 and one or more tines 1206 to prevent rotation of thespreader 1205. Such a rotation prevention feature may not be required ifthe inner tube 1207 is detached by breaking away from the spreader 1205.The proximal pulling of the inner tube 1207 may be effected by eithersliding the inner tube 1207 relative to the outer tube 1210 or byrotation with corresponding threads between the inner tube 1207 and theinside of the outer tube 1210 or other fixed portion of the inserter.Alternatively, the inserter described above with respect to FIGS. 4-10may be used.

FIG. 12C depicts the fully engaged expanded anchor 1201 and FIG. 12Ddepicts the fully expanded anchor 1201 with the inserter tool removedand the suture 1203 remaining. As in the previous embodiments, thespreader 1205 will remain permanently located in the anchor 1201 to helpprevent collapse, movement or slipping of the components and of theanchor 1201 as a whole. In one embodiment, illustrated in FIGS. 12B, 12Cand 12D, protrusions 1274 are provided on the inside of the tines 1206configured to snap into a groove 1272 located on the spreader 1205 whenthe tines 1206 are fully deployed. This feature provides improvedstability of the spreader 1205.

2. Alternative Tine Configuration

Another alternative embodiment is depicted in FIGS. 13A and 13B. In FIG.13A, an anchor 1300 comprises an anchor body comprising a proximalportion 1305 and a distal portion 1303. the anchor body also comprisesan axial bore 1302, anchor support legs 1307, tines 1310, and teeth1320. The anchor further comprises a spreader 1325. This embodiment alsocomprises ridges, sutures, an insertion tool, spreader notch and tinesgroove, (not shown in FIG. 13) similar to that depicted in FIG. 12. Inthis embodiment, a spreader 1325 is initially positioned distally fromthe anchor and the tines expand in the proximal end rather than thedistal end of the anchor. In FIG. 13B, the spreader is positioned withinthe distal portion 1303.

The anchor body 1305 comprises an axial bore 1302 and support legs 1307.The anchor body 1305 couples with the lower anchor 1303 such that thesupport legs 1307 fit alternately with the tines 1310 In thisembodiment, the anchor 1300 is configured such that the spreader 1325 isinserted into the anchor body through the axial bore in the distalportion 1303 and into the space between the tines of the anchor 1300. Asthe spreader 1325 is deployed, the reverse taper of the tines cause thetines to expand from the distal end outward towards the proximal end andengage the bone. The expanded tines 1310 rest below undrilled portionsof the bone cortex, thereby preventing the spreader 1325 from beingpulled out. The use of teeth 1320 in the tines 1310 is thereforeoptional. The spreader 1325 can have pre-attached sutures, which may beused to secure soft tissue. The suture passes through a hollow tube ofthe insertion tool 1335 and then out of the top of the insertion tool1335 for manual manipulation by a surgeon. An anchor insertion tool suchas described above may be used to insert the anchor, deploy thespreader, and detach the insertion tool thereby leaving suture strandsattached to the anchor 1350. Once fully expanded, a notch 1340 in thespreader engages a groove 1345 in the tines and becomes locked so thatthe spreader does not slip or reverse itself (as shown in FIG. 12).Alternatively, a ridge on the spreader may interface with a groove inthe anchor body.

The distal end of anchor 1300 comprises tines 1310 extending upwardsfrom the distal end of the anchor. The tines 1310 comprise teeth 1320,as previously described. The tines 1310 are narrower at their distalends and gradually wider in a lateral direction at their proximal endssuch that the inside surface of the tines tapers from its widest at theproximal end to the narrowest at the distal end. The distal end of theanchor comprises an axial bore. The spreader 1325 initially rests withinthe axial bore of the distal portion of the anchor body

The anchors depicted in FIGS. 12 and 13 can be made of biocompatible orphysiologically inert materials. Such materials include titanium and itsalloys, stainless steel, and cobalt based alloys. Bioabsorbablematerials can also be used. In some embodiments plastics such aspolyetheretherketone (PEEK) or other suitable materials may be used.

The exact size and dimensions of the anchor can vary with its intendeduse and the patient size. The following overall dimensions are suitedfor the shoulder and knee joints of an adult human of average size, andcan be modified for specific patients or uses. The diameter of theanchor can have, but is not limited to, a range from 3 to 10 mm.

3. Proximal Spreader Alternatives

In the following embodiments, the anchor generally comprises an anchorbody and a plurality of bendable tines extending distally from theanchor body. However, the spreader is configured to expand the tines bybeing “pushed” into the anchor body in a distal direction instead ofbeing “pulled” in the anchor body as in the embodiments described above.The tines may comprise a plurality of teeth. When the bendable tines areexpanded (bent outward), the teeth can engage the bone to hold theanchor in place. Some embodiments described herein include sutureattachment tabs. In some embodiments, the “push in” embodiment providesthe ability to be backed out after installation without further damageto the surrounding tissue or bone, and to retain the tissue by multiplesutures.

Some embodiments provide deformable suture attachment tabs on the anchorthat facilitate knotless attachment of sutures to the anchor within thesurgical site. In other embodiments, suture may be pre-attached tovarious locations on the anchor.

FIG. 14 depicts a non-limiting example of an anchor structure 1400 witha proximal spreader configuration. The anchor body 1402 can generallyhave any shape, for example a circular shape, or a polygon of three ormore sides. In the depicted embodiment, the anchor body 1402 has acircular shape with a axial bore 1404, which allows for insertion of atine spreader 1430, described below. The axial bore 1404 can generallybe any shape, for example, a circle shape or a polygon shape. Circularforms are preferred for the axial bore 1404

The distal end of the anchor body 1402 has a plurality of bendable tines1406 extending therefrom, as shown in FIG. 14. In one embodiment, theanchor body 1402 has from about two to about six bendable tines 1406extending therefrom. In a preferred embodiment, the anchor body 1402 hasthree bendable tines 1406 extending therefrom. The bendable tines 1406may be integrally joined with the anchor body 1402, either by machiningor injection molding a uniform piece of material or by stamping of asingle sheet of flat material. Alternatively, the tines 1406 may beattached to the anchor body 1402 such as by welding or adhesives. In thedepicted embodiment, the tines 1406 are formed by folding of a flatmaterial where the fold is along the longitudinal direction of the tine1406. Each bendable tine 1406 may comprise, along its outward-facingedge, one or more teeth 1410, preferably three to six in number, whichcan be engaged with the bone once the tines 1406 are spread apart afterinsertion of the anchor 1400. Each bendable tine's distal end can beformed to a slant or pointed edge. In other embodiments, the distal endof each bendable tine is either straight or any other effective shape.

The anchor is expandable at its distal end 1407 by the tines 1406spreading outward. As the bendable tines 1406 are spread apart with thespreader 1430 (described below), the teeth 1410 of the bendable tines1406 become engaged in bone material such that the anchor is securelyattached to the bone. Distal expansion provides improved pull-outstrength. Where multiple teeth 1410 are present, they may increase insize as they are positioned more distal from the anchor body 1402. Theteeth 1410 are preferably tapered to sharpened points that are able topenetrate tissue and/or the interior matrix (cancellous portion) of thebone. Once expanded, the spreader 1430 remains in the anchor 1400.

The bendable tines 1406 are preferably symmetrically positioned aboutthe anchor body 1402. In some embodiments, when the tines 1406 are intheir un-expanded configuration, the distal ends 1407 of the bendabletines 1406 are in a first internal lateral position, as depicted in FIG.14, such that they are parallel to or angled internal to thelongitudinal axis. In one embodiment, the internal angle is from about8° to about 15°. When in the internal lateral position, the teeth 1410may be at or within the cylindrical, axially extending region defined bythe axial body 1402. During and after insertion of a tine spreader, asthe distal ends 1407 of the tines 1406 are moved to their second orexternal, more lateral position, the distance between the ends 1407 andthe longitudinal axis of the anchor 1400 will increase to place thetines at or beyond the cylindrical axially extending region defined bythe anchor body 1402.

The anchor body 1402 may also comprise bendable tabs 1408, whichfunction as suture fasteners. The tabs 1408 may be integrally formedfrom the anchor body 1402 by cutting or drilling out of the anchor body1402. The tabs may also be formed during the stamping process shown inand described in FIG. 25, below. Alternatively, the tabs 1408 may beattached to the anchor body by welding or adhesives.

A tab 1408 may be round, triangular, square, or be of a non-regularshape. The tab 1408 is connected to the anchor in at least one portion.The collapsing of a tab 1408 can be caused, for instance, by bending,pressing, or exerting sufficient force onto the tab by the bone so thatat least part of it bends, thereby cinching a suture positioned behindthe tab 1408 in place. In some embodiments, the deformation isreversible. That is, after a first deformation of the tab 1408 whichcauses the suture to become fixedly attached to the anchor, the removalof the collapsing force can allow the tab 1408 to bend outward, therebyallowing the suture to become releasable from the anchor. In someembodiments such deformations causing suture fixation and release can beperformed multiple times. In other embodiments, such deformation canoccur only once or a limited number of times. For example, in oneembodiment, once the tab 1408 is deformed, it will not release even uponremoval of the collapsing force.

In a preferred embodiment, the tabs are flush with the outer surface ofthe anchor body. Sutures 1450 can be slid around the side of the tab oroptionally, can be threaded using a needle threader or any othermechanism. The nature of the suture thread is not critical.

In one embodiment, the tabs 1408 are flush with the anchor body outersurface. In other embodiments, the tabs 1408 extend laterally beyond theoutside surface of the anchor body 1402 prior to insertion of the anchor1400 into bone. In some embodiments, prior to complete insertion of theanchor 1400 into the bone, suture threads can be threaded or slid behindthe tabs 1408 on the anchor body 1402. In some embodiments, an optionalsuture threading device can be used. The threading portion of thethreading device may be a variety of shapes including curved orstraight. When the anchor 1400 is inserted fully into bone, the suturecan be held in place by pinching of the suture between the anchor body1402 and bone and pinching of the suture between the tabs 1408 and theanchor body 1402. In some embodiments, contact with the bone can causethe tabs 1408 to bend inward, thereby providing further pinching thesuture between the tabs 1408 and the anchor body 1402.

In the embodiment of FIG. 14, the tab 1408 is protruding outward, in aposition that has not locked or fixedly secured a suture (not shown) inplace yet. Applying pressure on the tab in direction of arrow H willcollapse the tab onto the top of anchor 1400, thereby fixedly lockingsuture against the anchor 1400. This may be accomplished by pressing theanchor into a bone hole such that the sides of bone hole force the tabs1408 inward. Alternatively, in some embodiments, the tabs 1408 may becollapsed prior to insertion of the anchor into bone by hand or by usingan insertion tool as shown below.

In embodiments depicted in FIGS. 14, 17, and 18A-18B (described below),the anchor body 1402 may optionally have holes 1420, 1820 extendinglaterally through the anchor body 1402. Such holes may be used, forexample, for threading of sutures and may be used in addition to oralternatively to other suture attachment features described herein, suchas deformable tabs or suture attachment to the spreader 1430. In theembodiment depicted in FIG. 14, there are two options for securing thesutures 1450, holes 1420 and tabs 1408, of which either or both may beused. The holes in the anchor body 1402 that are configured to receivesutures 1450 may be used alone as an alternative to the tabconfiguration. In such a configuration, the tabs to do not have to bepresent. FIGS. 18A and 18B depict embodiments in which tabs are notpresent. In the illustrated embodiment in FIGS. 14, 15, 17, and 18A-18B,the opening may accommodate an insertion tool, a spreader and anoptional cap, as described below.

As depicted in FIG. 15 which depicts another embodiment of the boneanchor 1400, the tabs 1408 can extend from the top of the anchor body1402. As illustrated in FIG. 15, the tabs 1408 may essentially replacethe outer surface of the anchor body 1402 in the positions at which theyare located. In other embodiments, the tabs 1408 may extend outward fromthe outer surface of the anchor body 1402. In still other embodiments asdepicted in FIG. 18, the tabs 102 may extend from the bottom end of theanchor body 1402. The tabs 1408 may be positioned at any locationscircumferentially around the anchor body 1402. In some embodiments, thetabs 1408 are positioned between each tine 1406.

In some embodiments, the sutures can be threaded under the tabs 1408before the anchor body 1402 is fully inserted into the bone whereby uponinsertion the tabs will be pushed flat against the anchor body therebysecuring or “pinching” the tabs into a secure position by collapsing thetab.

FIG. 16 shows another embodiment 1600 of an anchor 1400. In thisembodiment, laterally extending teeth 1410 are used to secure the anchor1600 in the bone. The anchor also has flexible tabs 1408, which may bebendable or hinged, and capable of being collapsed into a locking state.In this embodiment, the tabs 1408 have intermediate bends 1607, whichfacilitates collapsing of the tab 1408 when the bone contacts the bend1607. Collapsing the tab 1408 secures and locks any suture 1450 whichhas been placed beneath it, thereby capable of securing a suture to abone by means of the anchor. Applying pressure on the tabs 1408 indirection of arrow H will collapse the tabs 1408 inward, therebypinching the suture against other parts of the anchor 1600. Althoughthis embodiment has four tabs visible, generally one or more suchdeformable tabs may be present. The tabs can be bent or collapsed byinsertion of the anchor 1600 into bone or manually using a tool eitherprior to or during anchor insertion.

Although the suture capture tabs have been described with respect to the“push in” spreader embodiments, it will be appreciated that such tabsmay also be used with the “pull up” embodiments described above.

As discussed above, the bendable tines 1406 in the anchor may be in alow-profile streamlined position prior to insertion into bone. Aspreader 1430 may be used after insertion to expand the tines such thattheir teeth engage bone.

In the embodiment depicted in FIG. 17, the spreader 1430 is an elongatedstructure comprising a distally positioned head 1432 designed to contactthe tines 1406 and a proximally positioned shaft 1434 that is designedto interface with an insertion tool or cap (described below). Thespreader may comprise any suitable shape configured to be insertedthrough the axial bore 1404 in the anchor body 1402 and make contactwith the bendable tines 1406. The spreader 1430 may be at leastpartially positioned within the axial bore 1404 of the anchor prior totine expansion as depicted in FIG. 17. As the spreader 1430 is movedfrom a first upper position to a second lower position, the distal endof the spreader is designed to spread or force the tines 1406 from afirst low-profile position (for example, an internal lateral position)to a second external lateral position.

The spreader 1430 of FIG. 17 is designed to be slidably received by thehole in the anchor body 1404. In such embodiments, the spreader 1430 canhave a surface for receiving impact force and transmitting the forcesymmetrically down the length of the spreader 1430. The head 1432 can beflat or slightly concave to prevent slippage of the driver during use.In some embodiments, the head 1432 may have ridges to assist inpreventing slippage or mis-alignment.

The spreader 1430, whether slidably received or threaded, will remain inthe anchor 1400 with the tines 1406 in their fully spread position. Theforce provided by the tines' interaction with the bone keeps thespreader 1430 tightly engaged. Further protection against slipping ortilting of the spreader 1430 is provided by the optionally ridged sidesof the spreader 1430 and by an optional cap 1460. 1470. In someembodiments, the spreader head 1432 may have ridges or indentations toassist in a tight fit such that accidental slipping or adjustments areminimized while deliberate withdrawals are possible after insertion intobone without inadvertent pull-outs. In one embodiment, one or more ofthe tines 1406 have an indentation on a side facing the central axis ofthe anchor 1400. A ridge on the spreader head 1432 can then engage theindentation, thereby stabilizing the spreader 1430 and preventing thespreader 1430 from being advanced too far into the anchor. In analternative embodiment, the spreader head 1432 comprises an indentation(for example, an indentation in a ridge on the spreader head 1432) thatcan engage with a protrusion on a side of a tine facing the central axisof the anchor. In addition, to stabilizing the spreader and preventingover insertion, this feature also prevents rotation of the spreader 1430relative to the anchor.

FIG. 17 further illustrates an optional cap 1460 or 1470 that mayinterface with the spreader 1430 to keep it straight and prevent it frombeing pushed out after it has expanded the tines 1406. The cap 1460 or1470 can interface with the distal end of the shaft 1434 of the spreader1430. In some embodiments, the distal end of the shaft 1434 engages ahole or other receptacle in the cap 1460 and 1470. The cap 1460 or 1470can be secured to the anchor body 1402 of the anchor via threading 1470or snaps 1460. The screwing or snapping in of the cap 1460 or 1470 maybe accomplished by the insertion device, as outlined below, as a laststep of tine 1406 expansion. The cap 1460 or 1470 can also be optionallythreaded with sutures as an alternative to or in addition to the tabs orsuture holes in the anchor body 1402. In such an embodiment, the cap maybe pre-threaded with sutures 1450 prior to anchor insertion.

In another embodiment of a bone anchor 1800, the spreader 1830 isthreaded as in FIG. 18A and driven by torque. The threads of thespreader engage corresponding internal threads in the hole of the anchorbody 1802. In such an embodiment, the spreader 1830 can be single ormultiply slotted or comprise a socket such as a hexagonal socket forreceiving a complementary spreader rotational driver. In this case, thespreader 1830 can be screwed further into the anchor to cause expansionof the tines 1406, as depicted in FIG. 18B. When engaged with theinsertion tool, with or without the optional cap as described below, thespreader 1830 will advance down the anchor towards the distal end as itis rotated. As the spreader advances towards the distal end, the body ofthe spreader 1830 spreads the bendable tines 1406 away from the anchorbody. As the bendable tines 1406 expand, the tines become lodged in thebone thereby creating a locked position for the anchor 1800. Oneadvantage of this embodiment is that the spreader 1830 can be reversedand the anchor 1800 removed from the bone. This configuration alsoallows the spreader 1830 to be screwed back out to allow for adjustmentof the anchor or attached sutures.

In some embodiments when the cap 1460, 1470 is used as an alternative tothe tabs 1408 to secure the sutures, the sutures are pre-threaded beforeinsertion. As an alternative or as an addition to the suture securingmethod described above, a surgeon may choose to use the deformablesuture securing tabs 1408. In one embodiment, a length of suture can bepassed underneath the tab 1408 and tensioned in place. Then, the anchoris placed the rest of the way into the bone which pressure collapses thetab 1408 and fixedly secures the suture to the anchor.

4. Bone Anchor Insertion Tool for Proximal Spreader Alternative

The bone anchor device may be provided with an insertion tool designedto insert the bone anchor into bone and then deploy the spreader toexpand the tines 1406 on the bone anchor. Some embodiments of theinsertion tool are depicted in FIGS. 19, 20A and 20B. In general, theinsertion tool comprises a handle portion at a proximal end that can bemanipulated by a surgeon for inserting the bone anchor and deploying thespreader, and a bone anchor-engaging portion at a distal end that canattach to the anchor and move the spreader.

As described above, in some embodiments the spreader is advanced intothe bone anchor by the inserter tool by screwing into threads located inthe interior the anchor body, either using corresponding threads on thespreader itself as depicted in FIGS. 18A and 18B, or by a screw-in capas depicted in FIG. 17 element 1470, or by corresponding threads on aportion of the inserter tool. In such embodiments, the handle portion ofthe insertion tool can comprise features that facilitate rotationalmotion applied by the surgeon.

For example, one embodiment of such an insertion tool is depicted inFIG. 19 which depicts the inserter tool 1900 from a side perspective.Insertion tool 1900 comprises a longitudinally aligned handle 1902 thatallows the surgeon to apply an insertion force to the bone anchor.Insertion tool 1900 also comprises a laterally directed handle 1901 thatcan pivot around the longitudinal axis of the inserter 1900. Thisrotational motion can be used to rotate an inner pushing mechanism 1906,such as a tube or a rod that interfaces with a spreader or screw-in cap1470 as described below.

In some embodiments, the insertion tool may comprise an outer tube thatcan be reversibly coupled to the bone anchor, such as by snapping ontoor screwing onto threads on the outside of the anchor body. FIG. 20Adepicts such an embodiment. Outer tube 2004 is reversibly coupled to thebone anchor 1400 via threads allowing the inserter tool 2010 to beattached to the bone anchor 1400. Alternatively, tongue and groovesliding locks or magnets may be used or any other suitable engagementstructure. Engagement between the outer tube 2004 and the bone anchorallows the user to position and apply insertion force to the bone anchor1400 using the longitudinal handle 2002. In FIG. 20A, the embodimentfurther comprises an inner tube 2009 which pushes the spreader 1430distally in the bone anchor 1400. In the embodiment depicted in FIG.20A, the inner tube 2009 engages with a cap 1470 which in turninterfaces with the shaft of the spreader 1430. Rotation of the innertube or pushing mechanism 2009 rotates the spreader or cap to drive itinto the bone anchor and spread the bendable tines 1406 using either aspreader or cap with threads that interface with the anchor body 1402 orby threads on the inner pushing mechanism 2009 engaging with the anchorbody 1402. The inner pushing mechanism 2009 can interface with aspreader or screw-in cap hex structure or other driving feature.Alternatively, when the spreader 1430 is slidably received by the boneanchor 1400, the inserter 2010 of FIG. 20A may be designed such thatrotation of the lateral handle 2001 advances the inner rodlongitudinally, such as by threads within inserter 2010. In this case,the spreader and/or cap are advanced by the inner pushing mechanism 2009pushing them downward. Any other suitable handle configuration ormechanism can be used to facilitate a surgeon applying rotational motionto the inner pushing mechanism 2009.

In other embodiments, where the spreader 1430 is slidably received bythe bone anchor, the handle portion of the inserter may include featuresthat allow the inner pushing mechanism 2009 to be slid distally relativeto the outer tube 2004. For example, in one embodiment, the inserter2010 comprises a longitudinal handle feature positioned distally fromthe longitudinal handle 2002 that can slide distally over the outer tube2004. This feature may be coupled to the inner tube or pushing mechanism2009 to facilitate the distal sliding of the mechanism.

In another embodiment, a cross-sectional view of which is depicted inFIG. 20B, the insertion tool 2050 which comprises an outer tube 2060, anadvancing tube 2070 and an inner tube 2080, sutures 1450, an anchor1400, tines 1406, teeth 1410, tabs 1408, and a cap 1470. In thisembodiment, the slidably mounted outer sleeve 2060 fits over both thetube 2070 used to initially seat the bone anchor and also the innerpushing mechanism 2080 for driving the spreader, thereby providing threeconcentric elements for interfacing with the anchor and deploying thespreader 1430. After the anchor 1400 is inserted into the bone, theouter sleeve 2060 may be slid backward relative to the outer tube 2070and inner rod 2080. The sleeve 2060 makes contact with the anchor body1402 and properly positions and aligns the inserter tool 2050 relativeto the anchor 1400. The sleeve 2060 is used to initially place theanchor in a pre-drilled hole and may optionally be reversibly attachedto the anchor body 1402 by screwing onto threads or by snapping onto theanchor body 1402. The sleeve 2060 can also be used to hold the tabs1408, if present, in an inward compressed position during insertion ofthe anchor so that the tabs 1408 do not interfere with the insertion. Insome embodiments, slots may be provided in the sleeve 2060 so thatsutures can be slid behind the tabs 1408 when the sleeve 2060 is inposition over the anchor body 1402. After the anchor 1400 is positionedinto the bone, the sleeve 2060 may be slid backwards and the anchordriven all the way into the hole by applying force to the driver tube2080. Alternatively, the sleeve 2060 can remain in contact with theanchor body 1402 throughout anchor insertion. In some embodiments, thedriver tube 2080 only contacts the anchor body 1402 during anchorinsertion. In other embodiments, the driver tube 2080 is attached to theanchor body 1402 such as by snapping or screwing onto the anchor body1402.

The inner pushing mechanism 2080 is positioned within the driver tube2070 and can be slidably or rotationally driven to push the spreader 450through the anchor body 1402 to expand the tines 1406. The inner pushingmechanism 2080 can either drive the spreader directly or, as depicted inFIG. 15, push a snap-in 4200 or screw-in cap 1470 into the anchor body1402. The cap 1470 in turn simultaneously advances the spreader 1430. Insome embodiments, the cap, for example a snap-in cap 1460, canoptionally have pre-attached sutures. After insertion of the anchor anddeployment of the spreader 1430, the inserter may be decoupled from theanchor such as by unscrewing or unsnapping the sleeve 2060 and/or thedriver tube 2070 from the anchor body 1402.

In another embodiment, depicted in FIG. 21, the inserter 2100 comprisesa cam 2103 and lever 2101 configuration. The inserter tool 2100 has nomoving parts. In this embodiment, the predrilled hole is made to receivethe anchor (not shown) upon insertion. The surgeon then inserts theanchor (not shown). When the surgeon is ready to expand the tines of theanchor and engage with the bone, the surgeon would lift the lever 2101and the cam would force the inner rod 2112 to move the spreader (notshown) distally thereby engaging the tines with the bone.

In some embodiments, the insertion tool comprises a laterally extendingstopper, or flange 2205, as in FIG. 22. The stopper 2205 can be locatedon one side, both sides, or extend all the way around the inserter tool.The stopper 2205 rests on the top of the bone cortex once the anchor1400 is inserted, thereby preventing over-insertion and providing morestability for the insertion tool during the driving of the spreader. Inother embodiments, over-insertion is prevented by the preciselymeasuring the depth of the pre-drilled hole.

5. Suture Capture Alternative

In another embodiment, the sutures are attached to the bone anchor afterit has been inserted into the bone, for instance inside the patient'sshoulder or knee, as shown in FIG. 23. FIG. 23 depicts a one-piecesuture capture anchor which permits the sutures to be threaded throughthe cap while the insertion tool is inside the body. This embodimentcomprises an anchor 2300, an insertion tool 2301, a handle 2302, anouter tube 2304, an inner tube 2306, a cap 2308, one or more suturecapture loops 2310, and sutures 2314. Using this anchor, suture that isalready within the surgical site, such as from another already-insertedanchor or stitched to body tissue, may be captured at the point ofanchor insertion.

The bone is prepped for the bone anchor 2300. The top of the insertiontool 2301 includes a handle 2302 attached to the outer tube 2304 and theinner tube 2306 to facilitate a surgeon applying force to the insertiontool 2301. The outer tube 2304 is reversibly coupled to the anchor 2300,such as by snapping onto or screwing onto threads on the anchor body ofthe anchor 2300. The inner tube 2306 engages with a cap 2308 whichattaches by snapping or screwing to the shaft 2310 of the spreader 2312.The cap 2308 further comprises a series of nitinol loops 2310 which willthread the sutures 2314 once the anchor 2300 is engaged with the bone.

When the insertion tool 2301 is inserted into the body and the anchor2300 is engaged with bone, the inner tube 2306 can advance the cap 2308into the anchor such the surgeon can further snap or screw the cap 2308into the anchor 1400. During initial insertion and positioning of theanchor 1400, the cap 2308 has nitinol loops 2310 positioned just insidesuture holes through the cap 2308. The nitinol loops 2310 can then beadvanced to receive and capture the sutures 2314. The sutures 2314 canbe threaded through the loops 2310. When the nitinol loops 2310 arewithdrawn and the sutures 2314 are pulled through the suture holes andback outside of the body where they are available to the surgeon fortensioning. The surgeon can make all of the tensioning adjustments heneeds without having to have any loss of contact with the bone anchorbody 1400.

Another embodiment, shown as FIGS. 24A and 24B, shows a pre-threadedsliding cap embodiment. FIG. 24A illustrates the embodiment before thesutures are tensioned, and FIG. 24B illustrates the embodiment after thesutures are tensioned. The embodiment describes a first inserted anchor2402, a cap 2404, sutures 2406, a cannula 2408, and a second insertedbone anchor 2410.

In this embodiment, the surgeon takes the sutures 2406 from a firstinserted anchor 2402 of any type, which is already inserted and securedto bone, and threads the sutures 2406 through a capturing member such asa cap 2404 outside of the body, for instance, the shoulder. The cap 2404is then advanced down the sutures 2406 through the cannula 2408, andsnapped or otherwise fixedly attached to a pre-installed second boneanchor 2410 as previously described. This embodiment allows tensioningof the sutures 2406 2404 before final insertion of the cap 2404 into theanchor 2410, and thus the final capture of the sutures 2406. In someembodiments, the cap 2404 has ridges to ensure adequate suture pulloutforces. In other embodiments, the cap has a positive locking thatcrushes the suture as the cap is forced into place. It will beappreciated that this anchor may be employed with any suture alreadyavailable at the surgical site (for example, suture that has beenstitched to body tissue).

Although a particular inserter device for inserting and manipulating theanchor 1400 has been described, it should be understood that otherinserter designs may be used for manipulating the parts of anchor 1400described above to insert the anchor into bone and secure suturematerial to the anchor. For example, it may be possible to use separatetools for inserting the anchor and securing the suture material. In someembodiments, the collapsing of the tabs 1408 so that they do notinterfere with the insertion of the anchor may be accomplished byinstruments other than the inserter. For instance, the tabs may becompressed during anchor insertion by forceps, fingers, a rod, or anyother suitable mechanism, capable of deforming the tab.

Some embodiments include multi-component kits. The kits may include thetissue stabilizing device as described herein as a first component.Other components can include a drill and drill bits for forming a bonehole, sutures, and an inserter tool as described above. In someembodiments, the kit provides the anchor already engaged with theinserter tool ready for insertion. In some embodiments, the anchor isprovided with pre-attached sutures, such as sutures attached to thevarious spreader cap designs described above.

Method of Manufacturing

In one embodiment, the anchors described in FIGS. 14-24 herein aremanufactured by stamping of a sheet of flat material instead of bymachining or molding. First, a flat form is produced. The flat form canbe made of many different materials, for instance, such as metal (forinstance, titanium or stainless steel), plastic or fiberglass. A patternis then stamped out of the flat material. Alternatively, this flat formcan be shaped using a laser, chemical etching or some other suitablemethod.

After stamping of the flat material, the shape of the anchor is achievedby bending or folding the flat sheet.

FIG. 25 shows an embodiment of an anchor 1400 during an early stage inits manufacturing process. The anchor 1400 may be stamped from a singlesheet of metal foil or other pliable material using stamping dies andmethods that are common or well-known in the art. The shape of thestamped piece can include outlines for tabs 1408, adjustable tines 1406with teeth 1410, and an axial bore 1404 for receiving an insertion tool.Initially the stamped sheet may be largely two-dimensional. In order toform the final anchor, the tines 1406 can be bent or folded in anupwards direction to form a three-dimensional anchor. The tabs 1408 canalso be slightly bent upwards in order to form projecting protrusions.They can be fully bent such that they are substantially perpendicular tothe central plane of the anchor when a suture is ready to be locked inplace, in the various manners described previously. The embodimentshown, the anchor has three spiked tines 1406 and three tabs 1408;however, various numbers of tines and tabs can be used. The resultinganchor will have the shape depicted in FIG. 14.

In some embodiments, the anchor is made of polymeric materials and isformed by conventional machining using, for example, a CNC turretmachine. The anchor could also be injection molded.

Surgical Methods

Various embodiments include methods for attaching soft tissue to bone.In one embodiment, the methods include using the suture anchorsdescribed above.

In the preferred method, the procedure is performed arthroscopically;however, use of the anchor is not limited to any particular technique.Techniques for preparing an anchor insertion site, anchor insertion, andsuture handling are well-known in the art. For purposes ofexemplification, the details of one particular technique are providedbelow.

One method uses a 6 mm PEEK suture anchor, although different sizes andmaterials may be used. In one embodiment, the bone surface may beprepared with a drill bit or awl that creates a hole in the bone largeenough to receive the anchor. The cut hole can be either straight orangled to walls to form a Morse taper. One embodiment, as shown in FIG.26, anchors either having 2 or 4 suture strands (as described above) areused to perform a single row soft tissue repair (for example, a tornrotator cuff repair). FIG. 26A depicts an arthroscopic repair using asingle-row simple-suture technique with two anchors placed laterally tothe soft tissue. In the case of massive tears, 3 anchors may be used.Each anchor is typically loaded with either one strand (i.e., in 2-limbanchor) or two strands (i.e., in 4 limb anchor) of No. 2, nonabsorbable,ultra-high molecular weight polyethylene suture, although any suitablesuture material may be used. For rotator cuff repair, the anchorstypically are inserted 5 mm to 10 mm apart at the lateral edge of therotator cuff insertion footprint at 45° to the surface of the bone. Onehalf of the suture strands (i.e., one strand for 2-limb anchors or 2strands for 4-limb anchors) is passed through the tendon ˜10 mm from thefree edge. The sutures are typically tied by hand using a slipknot,followed by 3 alternating half hitches.

In other embodiments, suture capture anchors such as described in U.S.Patent Application Publication No. 2006-0004364, which is incorporatedherein by reference in its entirety, may be used in combination with theanchors described herein to create a variety of anchor and suturepatterns. In such embodiments, suture may be run from one of the anchorsdisclosed herein over soft tissue before being secured to a suturecapture anchor. In one embodiment, a double-row technique such as thatdepicted in FIG. 26B is used wherein the medial row utilizes the anchorsdescribed herein and the lateral row utilizes suture capture anchors.Two-strand or four-strand suture anchors 2650 and 2652 may be insertedbeneath the soft tissue along the medial row. The sutures may then bepassed over the soft tissue and captured with suture-capture anchors2654 and 2656 along the lateral row. In some embodiments (for examplewhen four-strand suture anchors are used) some suture strands may alsobe tied over the soft tissue. In certain embodiments, including thosedepicted in FIGS. 26A and 26B, multiple anchors and sutures may be usedto produce geometries such as depicted in FIG. 26B and variationsthereof.

In one embodiment, a hole is predrilled into the bone. In variousembodiments, the hole diameter is the same size, slightly larger, orslightly smaller than the diameter of the anchor. The smaller diameterhole provides an initial resistance to removal and stabilizes the anchorprior to deployment of the spreader. It will be appreciated that othermeans may be used to initially secure the anchor 100 to bone. Forexample, angled protrusions may be used that provide greater resistanceto removal of the anchor base 100 than to insertion. The protrusions maybe static or deployable once the anchor is inserted.

In another embodiment, the bone surface is optionally prepared with aawl or trocar that has a cutting surface that matches the anchor. Thisdistal end has an external size and configuration to create a hole inbone that complements the external configuration of the anchor body 200when its tines 220 are in the first position. The hole created by thetrocar should be the same size or just slightly smaller than theexternal size of the anchor 100 when in the undeployed position of FIG.1B. The trocar can be made of any material that can be sterilized, beformed into a cutting edge, and withstand the impact force needed topenetrate bone. Metal alloys such as stainless steel are preferred. Theoverall diameters of the trocar are not critical and need only be longenough to reach into the joint and extend outside a suitable distancefor receiving the impact force, or for drill attachment to a chuck. Anoverall length of eight to twelve inches with an outside diameter of 0.3to 1.5 cm is suitable for the anticipated uses.

Prior to anchor insertion, the spreader and the anchor can be mounted onan insertion tool. Alternatively, the insertion tool may be providedwith the anchor pre-attached.

In one embodiment, healing of damaged soft tissue and promotion of itsreattachment to bone may be aided through the use of a suture augment.Such an augment may be placed in contact with the soft tissue includingthe region where the tissue is damaged. In one embodiment, the sutureaugment is used to bridge gaps or span a defect between soft tissueincluding ligaments and tendons as well as gaps between the ligament ortendon to bone insertion points. Types of suture augments; variousgeometries of augments, sutures, and anchors; and methods for insertingand positioning augments are described in U.S. Application PublicationNo. 2007-0288023, which is incorporated herein by reference in itsentirety.

In embodiments comprising a suture tab, sutures may be threaded or slidbehind the tabs of the anchor, either within the surgical site oroutside of the body. In some embodiments, the sutures may be wrapped infront and behind the anchor or wrapped around tines of anchor to createa more tortuous path and therefore increased pullout strength. In someembodiments, suture may alternatively or also be pre-threaded throughpassageways formed through the anchor body of the anchor, through thespreader, or through a spreader cap. The anchor can then be pushed intothe pre-drilled bone hole and deployed while exerting downward pressureon the insertion tool. Generally, the anchor will be hand-driven,although machine-driven embodiments are possible as well. Finally, thespreader can be deployed using the various methods described above. Asused herein, “suture” refers to any flexible structure that can bestretched between two or more anchors and includes, without limitation,traditional suture material, single or multiple stranded threads, or amesh structure.

The suture attachment methods described in the previous paragraphs canbe done either before the anchor is inserted into the hole or else whenthe anchor is partially inserted but before the tabs and/or anchor body(some embodiments will not have tabs) are positioned below the surfaceof the bone.

In some embodiments, either before or after suture is coupled to theanchor, it is passed over the top of the soft tissue so that the suturecan press the soft tissue against the bone. In some embodiments,multiple lengths of suture attached to the anchor may be used.

The surgical procedures for which the anchors described herein areparticularly suited are repairs to the shoulder and knee joints such asreconstructing anterior cruciate ligament (ACL) deficiencies and forrepairing dislocating shoulders and torn rotator cuffs. However, theanchor is universally applicable to most efforts which warrantreattachment of soft tissue to bone. The brief description of surgicalprocedures herein are not intended to be the only way the embodimentsdescribed herein could be used and are presented for illustrationpurposes and not by way of limitation.

To place the anchor in its optimal position, one first conceptualizesthe goals of repair to identify the location where the anchor willprovide maximum security and adequate (isometric) function. Thepathology is then reprobed to locate tissue to be captured. The anchoralso provides for secure fixation in reconstruction cases, whereinautografts or allografts are used.

The surgeon then prepares the concavity for implanting the anchor by alimited synovectomy, burr notchplasty, and then by exposing bone. Thebone may be prepared with a tap or punch or drill or an appropriate holefor the bone anchor.

For example, in the case of a knee surgery, the surgeon then places theanchor into the anteromedial knee wound through an accommodatingcannula.

The anchor is then driven into the prepared concavity into thepre-drilled starter hold, while the knee is flexed at about 30°, and theassistant surgeon holds the tibia up towards the femur. The spreader isthen driven down or pulled up, thus expanding the prongs inside thebone, locking the anchor into place. The optional use of suturescompletes the repair. The surgeon tensions the sutures and checks thejoint clinically for stability and impingement. In embodiments, wheresuture tabs are used, the tensioning of the sutures may be conductedprior to complete insertion of the anchor. In other embodiments, thesutures may be threaded or pre-threaded through the anchor body and/orspreader caps (such as depicted in FIG. 17).

In one embodiment, a length of suture can be passed underneath the taband tensioned in place. Then the anchor is placed the rest of the wayinto the bone which pressure collapses the tab and fixedly secure thesuture to the anchor. In yet another embodiment the suture can bepre-tensioned before finally seating the snap-in or screw-in cap intothe anchor.

In a final step, the surgeon checks the joint motion, implant and jointstability, and rules out any impingement of the implant against mobilesurfaces.

Example in a Rotator Cuff Repair Procedure

One specific application in which the anchors described above may beutilized is a rotator cuff repair procedure, as depicted in FIGS. 27Athrough 27E. In this embodiment, a torn rotator cuff is repaired using atwo-point fixation technique where suture is attached between medial andlateral anchors. In the depicted embodiment, the medial anchor is ananchor that is inserted through the rotator cuff tissue and driven intounderlying bone. In FIG. 27A, the anchor 2700 is inserted through softtissue 2704 that has become detached from underlying bone 2706 anddriven into underlying bone. In FIG. 27B, the anchor 2700 is thendeployed to secure it into bone and its inserter 2702 is detached,leaving a suture 2708 attached to the bone anchor and extending throughthe soft tissue 2704. The anchor may be inserted into bone 2706 bytapping on the inserter 2702 with a hammer or by any other suitablemeans of applying axial force. FIG. 27C depicts the deployed anchor withattached suture. Any of the anchors described herein having pre-attachedsutures may be used for the medial anchor in this embodiment. In otherembodiments, an anchor such as described in U.S. Patent ApplicationPublication No. 2007-0142835, which is incorporated herein by referencein its entirety, may be used for the medial.

Next, as depicted in FIG. 27D, an anchor 2710, such as described above,is positioned within the surgical site laterally from the soft tissue2704 using an inserter 2712 The suture 2708 is passed over the softtissue 2704, tensioned, and secured to the anchor 2710. Any of theanchors described herein permitting suture attachment after anchorinsertion may be used for the medial anchor in this embodiment. In oneembodiment, the suture 2708 is secured by positioning it behind bendabletabs 2703 prior to complete insertion of the anchor 2710 into the bone.In other embodiments, the suture 2708 is attached to the anchor 2710using suture passages in the anchor body of the anchor 2710 or attachingit to the spreader or spreader cap. After the anchor 2710 is insertedinto the bone, the spreader may be deployed as described above. Theresult, FIG. 27E, is a length of suture 2708 stretched between the twobone anchors 2702 and 2710 that press the soft tissue 2704 against thebone In other embodiments, suture capture anchors such as described U.S.Patent Application Publication No. 2006-0004364, which is incorporatedherein by reference in its entirety, may be used for the lateral anchor2706.

Multiple anchors, anchors, and sutures may be used to produce geometriessuch as depicted in FIG. 28A-28D and variations thereof.

Some embodiments include multi-component kits. The kits may include theanchor as described herein as a first component. Other components caninclude a drill and drill bits for forming a bone hole, sutures, and aninserter tool as described above. In some embodiments, the kit providesthe anchor already engaged with the inserter tool ready for insertion.In some embodiments, the anchor is provided with pre-attached sutures,such as sutures attached to the various spreader designs describedabove.

In some embodiments, a pre-attached delivery handle is provided. In someembodiments, the insertion tool or delivery handle is disposable. Inother embodiments, the insertion tool can be sterilized, reloaded andreused.

Although particular inserter devices for inserting and manipulatinganchors have been described, it should be understood that other inserterdesigns may be used for manipulating the parts of anchors describedabove to insert the anchor into bone and secure tissue to the bone.

It will be appreciated by those of skill in the art that the embodimentsof the suture anchors and inserter tools provide a system for easyattachment of a tendon or other tissue to bone. The anchors may beinserted into bone with minimal disruption of surrounding tissue. Onlyan access route having the diameter of the outer portion of a insertiontool and the anchor body is required. Furthermore, the anchor can besecurely attached to the bone without having to insert additionalinstrumentation into the site or without performing any cumbersomeattachment maneuvers such as traditional knot tying.

It will be appreciated that there are numerous stitches, suturethreading patterns, and anchor patterns that may be used to secure softtissue to bone by the methods and devices described herein. Thesevariations as well as variations in the design of the above describedanchor devices and inserter devices are within the scope of the presentdisclosure.

All publications and patent applications cited in this specification areherein incorporated by reference as if each individual publication orpatent application were specifically and individually indicated to beincorporated by reference.

Although the foregoing embodiment has been described in some detail byway of illustration and example for purposes of clarity ofunderstanding, it will be readily apparent to those of ordinary skill inthe art in light of the teachings of this embodiment that certainchanges and modifications may be made thereto without departing from thespirit or scope of the appended claims.

1. An anchor for attaching tissue to bone, comprising: an anchor bodycomprising an axial bore and a plurality of bone-engaging tinesextending distally from the anchor body; a spreader comprising at leastone axial bore; and a suture extending through the at least one spreaderaxial bore and forming a loop on a distal end of the spreader, whereinthe spreader is configured to be positioned between the bone-engagingtines, and wherein the spreader is configured to expand the tinesoutward upon distal or proximal movement of the spreader relative to theanchor body.
 2. The anchor of claim 1, wherein the anchor body iscylindrical in shape.
 3. The anchor of claim 1, wherein thebone-engaging tines comprise teeth adapted to resist removal of theanchor from the bone.
 4. The anchor of claim 1, wherein thebone-engaging tines extend from a distal end of the anchor body.
 5. Theanchor of claim 1, wherein the bone-engaging tines extend from aproximal end of the anchor body.
 6. The anchor of claim 1, wherein thespreader comprises a proximal base and a distal spreader.
 7. The anchorof claim 6, wherein the proximal base is cylindrical in shape andfurther comprises an axial bore.
 8. The anchor of claim 7, wherein adistal portion of the spreader is cone-shaped
 9. The anchor of claim 8,wherein the spreader comprises a flat distal end surface.
 10. The anchorof claim 9, wherein the flat distal end surface further comprises anopening to the at least one spreader axial bore.
 11. The anchor of claim10, wherein the suture exits the opening and is knotted next to the flatend surface.
 12. The anchor of claim 1, wherein the at least onespreader axial bore is configured to couple to an inserter tool.
 13. Theanchor of claim 1, wherein the suture comprises a loop of suture whichextends through the at least one spreader axial bore and is knotted atthe distal end of the spreader such that the knot will not pass throughthe at least one axial bore.
 14. The anchor of claim 1, wherein thespreader comprises at least a portion that tapers proximally.
 15. Theanchor of claim 1, wherein the anchor body comprises a groove on aninside surface of at least one bone-engaging tine.
 16. The anchor ofclaim 15, wherein the spreader comprises a ridge configured to engagewith the groove.
 17. A bone anchor, comprising: a body comprising anaxial bore and a plurality of bone-engaging tines extending distallyfrom the anchor body; and a spreader positioned between thebone-engaging tines, wherein the spreader is configured to expand thetines outward upon distal movement of the spreader relative to theanchor body, wherein the spreader comprises two suture channels in itsdistal end configured in a cross pattern, wherein each channel isconfigured to receive a suture loop.
 18. The bone anchor of claim 17,wherein the two suture channels are perpendicular to each other.
 19. Thebone anchor of claim 17, wherein one of the two suture channels isdeeper in the spreader relative to the other.
 20. The bone anchor ofclaim 17, wherein the two suture channels open into the axial bore. 21.The bone anchor of claim 17, wherein an inside surface of at least onebone-engaging tine comprises a groove and wherein an outside surface ofthe spreader comprises a ridge and the spreader is configured to besecured between the bone-engaging tines by advancing the spreaderbetween the tines until the ridge snaps and secures within the groove.22. The bone anchor of claim 17, wherein the spreader comprises suturethreaded through each channel.
 23. A bone anchor inserter, comprising: aproximal handle portion; an outer tube coupled to the handle portion; anactuator coupled to the handle portion; an inner tube or rod coupled tothe actuator and located inside of the outer tube, wherein the actuatoris configured such that movement of the actuator relative to the handleportion causes the inner tube or rod to move axially relative to theouter tube; and an aperture in the handle portion configured to allowthe passing of sutures from the inner tube or rod to outside of theinserter.
 24. The inserter of claim 23 wherein the actuator isproximally coupled to a rotatable knob and distally coupled to the innertube or rod and wherein an outside surface of the inner tube or rodcomprises threads engaged with corresponding threads on the insidesurface of the actuator.
 25. A bone anchor and anchor insertercombination, the bone anchor comprising: an anchor body comprising anaxial bore and a plurality of bone-engaging tines extending distallyfrom the anchor body; a spreader positioned between the bone-engagingtines, wherein the spreader is configured to expand the tines outwardupon distal or proximal movement of the spreader relative to the anchorbody; at least one suture loop passing through the spreader; the anchorinserter comprising: a handle portion, an outer tube coupled to thehandle portion, an actuator coupled to the handle portion and the innertube, and an inner tube or rod coupled to the actuator and locatedinside of the outer tube, wherein the inner tube or rod is also coupledto the spreader, wherein the actuator is configured to such thatmovement of the actuator causes the inner tube or rod and hence thespreader to move axially relative to the outer tube.
 26. The anchor andinserter combination of claim 25, wherein the anchor inserter isconfigured to be broken off from the spreader after the anchor is fullydeployed.
 27. The anchor and inserter combination of claim 25, whereinan inside surface of at least one of the bone-engaging tines comprises agroove and the spreader comprises a ridge which limits the progressionof the spreader into the anchor body and which locks the spreader intoplace within the anchor body.
 28. The anchor and inserter combination ofclaim 25, wherein the handle portion comprises a rotatable portionconfigured to move the inner tube or rod proximally or distally uponrotation.
 29. A method of attaching tissue to bone, the methodcomprising: inserting a bone anchor in a pre-formed bone hole using aninsertion tool; advancing a spreader into the bone anchor using theinsertion tool to cause expansion of the anchor against bone;disengaging the insertion tool from the proximal end of the anchor;passing sutures which are secured to the spreader through the tissue;and fixedly securing the sutures on top of the tissue.
 30. The method ofclaim 29, wherein the bone anchor is fully inserted and secured to thebone before the anchor inserter tool is disengaged from the anchor.